{"product_id":"spa-frog-serene-bromine-cartridge-12-pack","title":"Spa Frog Serene Bromine Cartridge - 12 Pack","description":"\u003cdiv style=\"font-family:inherit;color:#1f2d33;line-height:1.6;max-width:100%;\"\u003e\n\u003cdiv style=\"background:#0b3954;color:#fff;border-radius:8px;padding:12px 16px;margin:0 0 12px;display:flex;align-items:center;gap:10px;flex-wrap:wrap;\"\u003e\n\u003cstrong style=\"font-size:1.08em;letter-spacing:0.02em;\"\u003eFree Shipping on this item in the USA\u003c\/strong\u003e\u003cspan style=\"opacity:0.9;\"\u003eOn online orders at HotTubPirate.com.\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#eef7f8;border-left:5px solid #0e7c86;border-radius:8px;padding:18px 20px;margin:0 0 1.4em;\"\u003e\n\u003ch2 id=\"overview\" style=\"color:#0b3954;font-size:1.3em;margin:0 0 0.6em;\"\u003eTwelve Yellow Bromine Cartridges for Busy Hot Tubs, Shipped Free\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eThe Spa Frog Serene Bromine Cartridge 12 Pack is twelve yellow 150 g bromine refills for FROG Serene Floating and In-Line systems. That is about six to eleven months of bromine for one hot tub, or a steady supply for rentals and homes with more than one hot tub.\u003c\/p\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eIt is the largest Serene bromine size we carry and ships free to US addresses on online orders at HotTubPirate.com.\u003c\/p\u003e\n\u003cdiv style=\"display:flex;flex-wrap:wrap;gap:10px;margin-top:6px;\"\u003e\n\u003cdiv style=\"flex:1 1 120px;min-width:120px;background:#fff;border:1px solid #d5e6e8;border-radius:8px;padding:10px 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:0.78em;text-transform:uppercase;letter-spacing:0.04em;color:#0e7c86;font-weight:600;\"\u003ePack\u003c\/div\u003e\n\u003cdiv style=\"font-size:1.02em;font-weight:700;color:#0b3954;\"\u003e12 Cartridges\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 120px;min-width:120px;background:#fff;border:1px solid #d5e6e8;border-radius:8px;padding:10px 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:0.78em;text-transform:uppercase;letter-spacing:0.04em;color:#0e7c86;font-weight:600;\"\u003eColor\u003c\/div\u003e\n\u003cdiv style=\"font-size:1.02em;font-weight:700;color:#0b3954;\"\u003eYellow\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 120px;min-width:120px;background:#fff;border:1px solid #d5e6e8;border-radius:8px;padding:10px 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:0.78em;text-transform:uppercase;letter-spacing:0.04em;color:#0e7c86;font-weight:600;\"\u003eCovers\u003c\/div\u003e\n\u003cdiv style=\"font-size:1.02em;font-weight:700;color:#0b3954;\"\u003e6–11 Months\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 120px;min-width:120px;background:#fff;border:1px solid #d5e6e8;border-radius:8px;padding:10px 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:0.78em;text-transform:uppercase;letter-spacing:0.04em;color:#0e7c86;font-weight:600;\"\u003eSystem\u003c\/div\u003e\n\u003cdiv style=\"font-size:1.02em;font-weight:700;color:#0b3954;\"\u003eSerene Floating\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 120px;min-width:120px;background:#fff;border:1px solid #d5e6e8;border-radius:8px;padding:10px 12px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:0.78em;text-transform:uppercase;letter-spacing:0.04em;color:#0e7c86;font-weight:600;\"\u003eShipping\u003c\/div\u003e\n\u003cdiv style=\"font-size:1.02em;font-weight:700;color:#0b3954;\"\u003eFree US Shipping\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch2 id=\"year-supply\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eMost of a Year in One Order\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eTwelve cartridges at 2 to 4 weeks each add up to roughly six to eleven months for one hot tub. Pair the box with two or three blue mineral cartridges and you are set for most of the year.\u003c\/p\u003e\n\u003ch2 id=\"heavy-use\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eBuilt for Rentals and Heavy Use\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eVacation rentals, large families and frequent soakers go through bromine faster. A dozen cartridges on hand means a fresh one is always ready.\u003c\/p\u003e\n\u003ch2 id=\"free-shipping\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eFree US Shipping on Online Orders\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eThe 12 Pack ships free within the US when you order online at HotTubPirate.com.\u003c\/p\u003e\n\u003ch2 id=\"key-features\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eKey Features and Benefits\u003c\/h2\u003e\n\u003cul style=\"display:flex;flex-wrap:wrap;gap:12px;padding:0;margin:0 0 1em;\"\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003e12 Yellow Cartridges\u003c\/strong\u003e150 g of prefilled bromine each.\u003c\/li\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003eAbout 6–11 Months\u003c\/strong\u003eFor one hot tub at 2 to 4 weeks each.\u003c\/li\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003eRental and Multi-Tub Ready\u003c\/strong\u003eKeeps several floaters supplied.\u003c\/li\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003eFree US Shipping\u003c\/strong\u003eOn online orders at HotTubPirate.com.\u003c\/li\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003eFloating or In-Line\u003c\/strong\u003eFits the floater or built-in holder.\u003c\/li\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003eAdjustable 0–6\u003c\/strong\u003eMatched to 200 to 600 gallons.\u003c\/li\u003e\n\u003cli style=\"flex:1 1 230px;min-width:220px;list-style:none;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:12px 14px;margin:0;\"\u003e\n\u003cstrong style=\"color:#0b3954;display:block;margin-bottom:2px;\"\u003eEPA Registered\u003c\/strong\u003eEPA Reg. No. 53735-16.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 id=\"product-details\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eProduct Details\u003c\/h2\u003e\n\u003cdiv style=\"overflow-x:auto;margin:0 0 1em;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:0.95em;\"\u003e\n\u003ccaption style=\"text-align:left;font-size:0.85em;color:#5b6b70;padding-bottom:6px;\"\u003eSpa Frog Serene Bromine Cartridge - 12 Pack specifications\u003c\/caption\u003e\n\u003cthead\u003e\u003ctr style=\"background:#0b3954;color:#fff;\"\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eProduct Detail\u003c\/th\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eInformation\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eBrand\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eFROG (King Technology, Inc.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eProduct\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eSpa Frog Serene Bromine Cartridge - 12 Pack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003ePack Size\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e12 cartridges\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eCartridge Size\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e150 g (5.3 oz) net per cartridge\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eTotal Contents\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e1,800 g (12 × 150 g)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eCartridge Color\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eYellow\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eProduct Type\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003ePrefilled bromine sanitizer cartridge for hot tubs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eActive Ingredient\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eBCDMH (1-bromo-3-chloro-5,5-dimethylhydantoin), 98.0%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eOther Ingredients\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e2.0%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eContents Form (SDS)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eWhite tablets or granules sealed inside the cartridge\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eMade For\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eFROG Serene Floating System and FROG Serene In-Line System\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eUse With\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eFROG Serene Mineral Cartridge (blue), set to #6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eHot Tub Size\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eAbout 200–600 gallons on the setting chart\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eAdjustable Settings\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e0 to 6, matched to hot tub gallons\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eTarget Bromine Level\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e1.0–2.0 ppm, at least 1.0 ppm at all times\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eWater Balance (Floating Manual)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003epH 7.2–7.6, total alkalinity 80–120 ppm, total hardness 150–250 ppm, TDS under 1,500, cyanuric acid 0–50 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eTypical Cartridge Life\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eAbout 2 to 4 weeks, depending on hot tub size and use\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eRefillable\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eRecommended Shock\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eFROG Maintain non-chlorine shock, weekly or as needed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eHolder or Floater Included\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eHazard Classification (SDS)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eDanger: corrosive, causes severe skin burns and eye damage, harmful if swallowed or inhaled, may cause an allergic skin reaction, oxidizer\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eStorage\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eOriginal packaging, tightly closed and upright, cool and ventilated, at or below 86°F (30°C), locked up\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eShipping Note (SDS)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eShipped under Limited Quantities provisions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eEPA Registration No.\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e53735-16\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eCalifornia Registration No.\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e53735-16-AA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eManufacturer Part Number\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e01-14-3824 (12 single cartridges)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eStore SKU\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e01-14-3824-12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eUPC\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e722906038214 (single cartridge)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eEstimated Supply\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eAbout 6 to 11 months for one hot tub\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;width:42%;\"\u003eImage Alt Text\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eTwelve yellow Spa Frog Serene 150 g bromine cartridges in two rows of six for FROG Serene Floating and In-Line systems, 12 pack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003ch2 id=\"how-to-use\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eHow to Use the FROG Serene Bromine Cartridge\u003c\/h2\u003e\n\u003col style=\"list-style:none;padding:0;margin:0 0 1em;\"\u003e\n\u003cli style=\"display:flex;gap:12px;align-items:flex-start;margin:0 0 10px;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"flex:0 0 30px;height:30px;border-radius:50%;background:#0e7c86;color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;\"\u003e1\u003c\/span\u003e\u003cspan\u003e\u003cstrong style=\"color:#0b3954;\"\u003eBalance the water first:\u003c\/strong\u003e Test with \u003ca href=\"\/products\/frog-test-strips-pools-hot-tubs-50-count\" style=\"color:#0e7c86;font-weight:600;\"\u003eFROG Test Strips\u003c\/a\u003e and adjust total alkalinity to 80–120 ppm, then pH to 7.2–7.6, then hardness to 150–250 ppm. Add one balancer at a time with the jets on and wait 6 hours before retesting.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex;gap:12px;align-items:flex-start;margin:0 0 10px;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"flex:0 0 30px;height:30px;border-radius:50%;background:#0e7c86;color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;\"\u003e2\u003c\/span\u003e\u003cspan\u003e\u003cstrong style=\"color:#0b3954;\"\u003eStart up with FROG Jump Start:\u003c\/strong\u003e After a fresh fill, set a starting level of 1.0–2.0 ppm with one Jump Start packet per 600 gallons. FROG says not to use a non-chlorine shock at start-up.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex;gap:12px;align-items:flex-start;margin:0 0 10px;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"flex:0 0 30px;height:30px;border-radius:50%;background:#0e7c86;color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;\"\u003e3\u003c\/span\u003e\u003cspan\u003e\u003cstrong style=\"color:#0b3954;\"\u003eSet both cartridges:\u003c\/strong\u003e Turn the blue mineral cartridge to #6. Turn the yellow bromine cartridge to the number on the setting chart for your hot tub's gallons.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex;gap:12px;align-items:flex-start;margin:0 0 10px;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"flex:0 0 30px;height:30px;border-radius:50%;background:#0e7c86;color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;\"\u003e4\u003c\/span\u003e\u003cspan\u003e\u003cstrong style=\"color:#0b3954;\"\u003eSnap them into the floater:\u003c\/strong\u003e Push both cartridges into the openings of the green FROG Serene Floating System holder until they stay in place, then let it float in the hot tub.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex;gap:12px;align-items:flex-start;margin:0 0 10px;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"flex:0 0 30px;height:30px;border-radius:50%;background:#0e7c86;color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;\"\u003e5\u003c\/span\u003e\u003cspan\u003e\u003cstrong style=\"color:#0b3954;\"\u003eFine-tune for a week:\u003c\/strong\u003e Test daily for the first week and move the bromine cartridge up or down one number per day until the strip matches 1.0–2.0 ppm.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli style=\"display:flex;gap:12px;align-items:flex-start;margin:0 0 10px;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"flex:0 0 30px;height:30px;border-radius:50%;background:#0e7c86;color:#fff;font-weight:700;display:flex;align-items:center;justify-content:center;\"\u003e6\u003c\/span\u003e\u003cspan\u003e\u003cstrong style=\"color:#0b3954;\"\u003eSwap the yellow cartridge when empty:\u003c\/strong\u003e Replace it when it runs out, usually every 2 to 4 weeks. Drain the water out of the old one, then discard it or recycle it where available.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.08em;margin:1.2em 0 0.4em;\"\u003eFROG Serene Bromine Cartridge Setting Chart\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x:auto;margin:0 0 1em;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:0.95em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#0b3954;color:#fff;\"\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eHot Tub Size\u003c\/th\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eBromine Cartridge Setting\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e200 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e0\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e250 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e300 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e350 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e400 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e450 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e500 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e550 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e600 gallons\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eFrom the FROG Serene Floating and In-Line manuals. The blue mineral cartridge always goes on #6. For the first week, test daily and move the bromine cartridge up or down one setting per day until the strip reads 1.0 to 2.0 ppm bromine.\u003c\/p\u003e\n\u003ch2 id=\"compatibility\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eCompatibility Notes\u003c\/h2\u003e\n\u003cdiv style=\"background:#fff8e6;border:1px solid #e0b44c;border-left:5px solid #e0b44c;border-radius:8px;padding:14px 16px;margin:0 0 1em;\"\u003e\n\u003ch3 style=\"color:#8a5a00;font-size:1.05em;margin:0 0 0.4em;\"\u003eBefore You Buy\u003c\/h3\u003e\n\u003cul style=\"margin:0;padding-left:20px;\"\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eThis is the yellow 150 g FROG Serene Bromine Cartridge. FROG's 2026 catalog lists it for both the FROG Serene Floating System and the FROG Serene In-Line System.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eIn a built-in FROG Serene In-Line holder it goes in the bottom position, under the blue mineral. FROG also makes a larger green 200 g bromine cartridge, mainly for in-line holders. FROG Serene bromine cartridges of either size work in both the floater and in-line holders.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eIt needs a blue FROG Serene Mineral Cartridge alongside it. FROG notes the lower bromine level only applies when FROG minerals are in use.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eNot for FROG @ease systems, which use SmartChlor chlorine cartridges instead of bromine.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eSized for hot tubs from about 200 to 600 gallons on the setting chart. FROG's floating system page lists hot tubs of 150 to 600 gallons.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eThe cartridge holder or floater is not included. This listing is the replacement cartridge only.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.08em;margin:1.2em 0 0.4em;\"\u003eWhich FROG Serene Cartridge Do I Need?\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x:auto;margin:0 0 1em;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:0.95em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#0b3954;color:#fff;\"\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eCartridge\u003c\/th\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eMade For\u003c\/th\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eReplace\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003eFROG Serene Mineral Cartridge (blue)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eSerene Floating and Serene In-Line\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eEvery 4 months, or at each drain and refill\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003eFROG Serene Bromine Cartridge, 150 g (yellow)  (this listing)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eSerene Floating and Serene In-Line\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eWhen empty, about every 2 to 4 weeks\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003eFROG Serene In-Line Bromine Cartridge, 200 g (green)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eMainly Serene In-Line (also fits Floating)\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eWhen empty, about every 2 to 4 weeks\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003eFROG Serene Cartridge Kit (1 blue + 3 yellow)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eSerene Floating or In-Line refill\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eOne mineral cycle plus three bromine changes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003eFROG Serene In-Line Refill (1 blue + 1 green)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eSerene In-Line refill\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eOne mineral cycle plus one bromine change\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003eFROG @ease cartridges\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eFROG @ease systems only\u003c\/td\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eSeparate SmartChlor system, not interchangeable with Serene\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eColors help you tell them apart: blue is always the mineral, yellow is the 150 g bromine and green is the larger 200 g bromine, made mainly for in-line holders. Either bromine size fits both Serene systems.\u003c\/p\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.08em;margin:1.2em 0 0.4em;\"\u003eHow Long Each Pack Lasts\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x:auto;margin:0 0 1em;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:0.95em;\"\u003e\n\u003cthead\u003e\u003ctr style=\"background:#0b3954;color:#fff;\"\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003ePack\u003c\/th\u003e\n\u003cth scope=\"col\" style=\"text-align:left;padding:10px 12px;border:1px solid #0b3954;\"\u003eOne Hot Tub, One Cartridge at a Time\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e1 cartridge\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003e2–4 weeks\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e3 Pack\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eAbout 6–12 weeks\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#eef7f8;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e6 Pack\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eAbout 3–6 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#fff;\"\u003e\n\u003cth scope=\"row\" style=\"text-align:left;padding:9px 12px;border:1px solid #d5e6e8;color:#0b3954;font-weight:600;\"\u003e12 Pack  (this listing)\u003c\/th\u003e\n\u003ctd style=\"padding:9px 12px;border:1px solid #d5e6e8;\"\u003eAbout 6–11 months\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eBased on FROG's 2 to 4 week cartridge life. Large hot tubs, frequent soaks and heavy bather loads empty cartridges sooner. Remember the blue mineral cartridge also needs replacing every 4 months.\u003c\/p\u003e\n\u003ch2 id=\"why-choose\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eWhy Choose the Spa Frog Serene Bromine 12 Pack\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eOne box of genuine yellow cartridges covers most of a year for a single hot tub, or keeps busy and rental hot tubs supplied, and it ships free on online orders. Shop the full \u003ca href=\"\/collections\/frog-serene\" style=\"color:#0e7c86;font-weight:600;\"\u003eFROG Serene line\u003c\/a\u003e, or compare every \u003ca href=\"\/collections\/bromine\" style=\"color:#0e7c86;font-weight:600;\"\u003ehot tub bromine\u003c\/a\u003e option at HotTubPirate.com.\u003c\/p\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.08em;margin:1.2em 0 0.4em;\"\u003eIdeal For\u003c\/h3\u003e\n\u003cul style=\"padding-left:0;margin:0 0 1em;list-style:none;\"\u003e\n\u003cli style=\"margin:0 0 6px;padding-left:26px;position:relative;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"position:absolute;left:0;color:#0e7c86;font-weight:700;\"\u003e✓\u003c\/span\u003eVacation rentals\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;padding-left:26px;position:relative;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"position:absolute;left:0;color:#0e7c86;font-weight:700;\"\u003e✓\u003c\/span\u003eHomes with two or more hot tubs\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;padding-left:26px;position:relative;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"position:absolute;left:0;color:#0e7c86;font-weight:700;\"\u003e✓\u003c\/span\u003eFrequent soakers\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;padding-left:26px;position:relative;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"position:absolute;left:0;color:#0e7c86;font-weight:700;\"\u003e✓\u003c\/span\u003eMost of a year of bromine\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;padding-left:26px;position:relative;\"\u003e\n\u003cspan aria-hidden=\"true\" style=\"position:absolute;left:0;color:#0e7c86;font-weight:700;\"\u003e✓\u003c\/span\u003eShoppers who want free shipping\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 id=\"faq\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eIs a 12 pack enough bromine for a full year?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eFor many hot tubs it covers most of one. At FROG's 2 to 4 weeks per cartridge, twelve last about six to eleven months. A lightly used hot tub gets closest to a year.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eI have a built-in FROG holder. Should I buy the yellow or the green cartridge?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eEither works. FROG's 2026 catalog lists the yellow 150 g for the In-Line System, and FROG also makes a green 200 g cartridge that holds more bromine per change. This pack is the yellow 150 g size.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eCan I refill these cartridges to make the pack last longer?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eNo. FROG labels them non-refillable. Using a fresh cartridge each time keeps the bromine output matched to the setting chart.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eWhat is the setting for a 400 gallon hot tub?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eSetting 3 on FROG's chart. Smaller hot tubs use lower numbers, down to 0 at 200 gallons, and larger ones go up to 6 at 600 gallons.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eWhat does FROG mean by Fresh Mineral Water?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eIt is FROG's name for water treated with its minerals plus a low level of sanitizer. FROG describes it as cleaner, clearer, softer and easier to care for than bromine alone.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eWhat is BCDMH?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eBCDMH is bromochlorodimethylhydantoin, the active ingredient in the cartridge at 98.0%. It dissolves slowly in water and releases bromine to sanitize.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eDoes the FROG Serene bromine cartridge add cyanuric acid?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eNo. BCDMH is a hydantoin, not a cyanurate, so it does not add cyanuric acid. That is one reason FROG recommends non-chlorine FROG Maintain instead of dichlor shock with Serene.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eCan I recycle the empty cartridges?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eFROG's manual says to drain each spent cartridge and discard it in the trash or offer it for recycling if available. Check what your local program accepts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eCan I use FROG Serene cartridges in a swim spa?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eThe Serene setting chart covers hot tubs from 200 to 600 gallons. Swim spas hold far more water, so these cartridges are not sized for them.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eDoes the 12 pack include the floating holder?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eNo. The pack is twelve replacement cartridges only. They go into the FROG Serene floater or built-in Serene holder you already have, beside the blue mineral cartridge.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eHow many mineral cartridges go with 12 bromine cartridges?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eTwo or three. Twelve bromine cartridges last about 24 to 48 weeks, and the blue mineral cartridge is replaced every 4 months, or at each drain and refill.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eWhat does 5.3 oz on the label mean?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eThat is the net weight of bromine sanitizer in each cartridge, 150 g. Across the 12 pack it comes to 1,800 g of prefilled bromine.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eDo I need to drain the hot tub to change a bromine cartridge?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eNo. Swap the yellow cartridge whenever it empties. Draining and refilling follows your hot tub maker's schedule, and that is when FROG says to replace the blue mineral cartridge too.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eWhat else should I keep on hand with FROG Serene?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eFROG Test Strips, FROG Maintain for weekly shocking, a FROG Jump Start packet for each fresh fill and a blue FROG Serene Mineral Cartridge for each 4-month change.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #d5e6e8;border-radius:8px;padding:12px 16px;margin:0 0 10px;background:#fff;\"\u003e\n\u003ch3 style=\"color:#0b3954;font-size:1.03em;margin:0 0 0.35em;\"\u003eCan I buy the blue mineral cartridge separately?\u003c\/h3\u003e\n\u003cp style=\"margin:0;\"\u003eYes. The FROG Serene Mineral Replacement Cartridge is sold on its own and as a 2 pack, so you can add one for every 4-month change alongside this box of bromine.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch2 id=\"safety\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eSafety Notes\u003c\/h2\u003e\n\u003cdiv style=\"background:#fdf1f0;border:1px solid #e4a29b;border-left:5px solid #e4a29b;border-radius:8px;padding:14px 16px;margin:0 0 1em;\"\u003e\n\u003ch3 style=\"color:#b42318;font-size:1.05em;margin:0 0 0.4em;\"\u003eHandle With Care\u003c\/h3\u003e\n\u003cul style=\"margin:0;padding-left:20px;\"\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eDanger: corrosive. The bromine inside causes severe skin burns and eye damage and is harmful if swallowed or inhaled. Wear gloves and eye protection when you handle or drain a cartridge.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eDo not open, break or refill the cartridge, and do not handle a damaged cartridge without protective gear.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eStrong oxidizer. Keep it away from heat, flames and combustible materials, and never mix it with other chemicals.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eDo not use it in a feeder or other device that has been used with calcium hypochlorite.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eIf it gets in the eyes, rinse cautiously with water for several minutes, remove contact lenses if easy to do, keep rinsing and call a poison center or doctor right away.\u003c\/li\u003e\n\u003cli style=\"margin:0 0 6px;\"\u003eStore cartridges in the original packaging, tightly closed and upright, in a cool, well-ventilated place at or below 86°F (30°C), locked up and away from children and pets.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\u003cdiv class=\"htp-product-documents\" style=\"font-family:inherit;color:#1f2d33;line-height:1.6;\"\u003e\n\u003ch2 id=\"product-documents\" style=\"color:#0b3954;font-size:1.35em;margin:1.6em 0 0.6em;padding-bottom:6px;border-bottom:2px solid #0e7c86;\"\u003eProduct Documents\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 0.9em;\"\u003eDownload the FROG Serene Floating System and In-Line System manuals for the setting chart and replacement steps, plus the official Safety Data Sheet for the bromine cartridge.\u003c\/p\u003e\n\u003cdiv style=\"display:flex;flex-wrap:wrap;gap:12px;margin:0 0 1.2em;\"\u003e\n\u003cdiv style=\"flex:1 1 260px;min-width:230px;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;\"\u003e\n\u003cdiv style=\"flex:0 0 auto;background:#0b3954;color:#fff;font-weight:700;font-size:0.75em;letter-spacing:0.05em;border-radius:6px;padding:10px 8px;line-height:1;\"\u003ePDF\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 auto;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#0b3954;margin:0 0 4px;\"\u003eFROG Serene Floating System Manual\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.9em;color:#5b6b70;margin:0 0 10px;\"\u003eSet-up, setting chart, cartridge replacement and troubleshooting (PDF, 2 pages)\u003c\/div\u003e\n\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0269\/2625\/2077\/files\/frog-serene-floating-system-manual.pdf\" target=\"_blank\" rel=\"noopener\" style=\"display:inline-block;background:#0e7c86;color:#fff;text-decoration:none;font-weight:600;font-size:0.92em;padding:8px 14px;border-radius:6px;\"\u003eView or Download Instructions\u003c\/a\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px;min-width:230px;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;\"\u003e\n\u003cdiv style=\"flex:0 0 auto;background:#0b3954;color:#fff;font-weight:700;font-size:0.75em;letter-spacing:0.05em;border-radius:6px;padding:10px 8px;line-height:1;\"\u003ePDF\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 auto;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#0b3954;margin:0 0 4px;\"\u003eFROG Serene In-Line System Manual\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.9em;color:#5b6b70;margin:0 0 10px;\"\u003eHolder removal, cartridge placement, setting chart and routine care (PDF, 2 pages)\u003c\/div\u003e\n\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0269\/2625\/2077\/files\/frog-serene-in-line-system-manual.pdf\" target=\"_blank\" rel=\"noopener\" style=\"display:inline-block;background:#0e7c86;color:#fff;text-decoration:none;font-weight:600;font-size:0.92em;padding:8px 14px;border-radius:6px;\"\u003eView or Download Instructions\u003c\/a\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px;min-width:230px;background:#fff;border:1px solid #d5e6e8;border-top:3px solid #0e7c86;border-radius:8px;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;\"\u003e\n\u003cdiv style=\"flex:0 0 auto;background:#0b3954;color:#fff;font-weight:700;font-size:0.75em;letter-spacing:0.05em;border-radius:6px;padding:10px 8px;line-height:1;\"\u003ePDF\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 auto;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#0b3954;margin:0 0 4px;\"\u003eSafety Data Sheet: Bromine Cartridge\u003c\/div\u003e\n\u003cdiv style=\"font-size:0.9em;color:#5b6b70;margin:0 0 10px;\"\u003eFROG Serene Bromine Cartridge Safety Data Sheet (PDF, Rev. 03, October 2022)\u003c\/div\u003e\n\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0269\/2625\/2077\/files\/frog-serene-bromine-cartridge-sds.pdf\" target=\"_blank\" rel=\"noopener\" style=\"display:inline-block;background:#0e7c86;color:#fff;text-decoration:none;font-weight:600;font-size:0.92em;padding:8px 14px;border-radius:6px;\"\u003eView or Download SDS\u003c\/a\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"FROG","offers":[{"title":"Default Title","offer_id":68070852100283,"sku":"01-14-3824-12","price":191.4,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0269\/2625\/2077\/files\/frog-serene-bromine-cartridge-12-pack.jpg?v=1793559797","url":"https:\/\/hottubpirate.com\/products\/spa-frog-serene-bromine-cartridge-12-pack","provider":"Hot Tub Pirate","version":"1.0","type":"link"}