Description
Three Yellow Bromine Refills for Your FROG Serene Floater
The Spa Frog Serene Bromine Cartridge 3 Pack gives you three of the yellow 150 g bromine cartridges used in FROG Serene Floating and In-Line systems. At FROG's typical 2 to 4 weeks per cartridge, that is roughly six to twelve weeks of bromine.
Keep two on the shelf while one is working, so a fresh cartridge is ready the day the old one runs dry.
Never Wait on a Refill
Cartridges usually run out between test days. With two spares in the cupboard, you swap in a new one right away and the bromine level never drops while you wait on an order.
Most of a Mineral Cycle in One Box
The blue mineral cartridge lasts 4 months. Three bromine cartridges cover a good part of that stretch, and a lightly used hot tub may get close to the next mineral change.
The Same Genuine 150 g Cartridge
These are the same FROG Serene 150 g yellow cartridges sold individually, order code 01-14-3824, with the same 0 to 6 setting dial and fit in the floater.
Key Features and Benefits
- 3 Yellow Cartridges150 g of prefilled bromine in each.
- About 6–12 WeeksAt 2 to 4 weeks per cartridge.
- Fits the Serene FloaterSnaps in beside the blue mineral.
- Adjustable 0–6Matched to 200 to 600 gallons.
- No MeasuringSealed bromine, nothing to scoop.
- Spares ReadySwap the day one runs out.
- EPA RegisteredEPA Reg. No. 53735-16.
Product Details
| Product Detail | Information |
|---|---|
| Brand | FROG (King Technology, Inc.) |
| Product | Spa Frog Serene Bromine Cartridge - 3 Pack |
| Pack Size | 3 cartridges |
| Cartridge Size | 150 g (5.3 oz) net per cartridge |
| Total Contents | 450 g (3 × 150 g) |
| Cartridge Color | Yellow |
| Product Type | Prefilled bromine sanitizer cartridge for hot tubs |
| Active Ingredient | BCDMH (1-bromo-3-chloro-5,5-dimethylhydantoin), 98.0% |
| Other Ingredients | 2.0% |
| Contents Form (SDS) | White tablets or granules sealed inside the cartridge |
| Made For | FROG Serene Floating System and FROG Serene In-Line System |
| Use With | FROG Serene Mineral Cartridge (blue), set to #6 |
| Hot Tub Size | About 200–600 gallons on the setting chart |
| Adjustable Settings | 0 to 6, matched to hot tub gallons |
| Target Bromine Level | 1.0–2.0 ppm, at least 1.0 ppm at all times |
| Water Balance (Floating Manual) | pH 7.2–7.6, total alkalinity 80–120 ppm, total hardness 150–250 ppm, TDS under 1,500, cyanuric acid 0–50 ppm |
| Typical Cartridge Life | About 2 to 4 weeks, depending on hot tub size and use |
| Refillable | No |
| Recommended Shock | FROG Maintain non-chlorine shock, weekly or as needed |
| Holder or Floater Included | No |
| Hazard Classification (SDS) | Danger: corrosive, causes severe skin burns and eye damage, harmful if swallowed or inhaled, may cause an allergic skin reaction, oxidizer |
| Storage | Original packaging, tightly closed and upright, cool and ventilated, at or below 86°F (30°C), locked up |
| Shipping Note (SDS) | Shipped under Limited Quantities provisions |
| EPA Registration No. | 53735-16 |
| California Registration No. | 53735-16-AA |
| Manufacturer Part Number | 01-14-3824 (3 single cartridges) |
| Store SKU | 01-14-3824-3 |
| UPC | 722906038214 (single cartridge) |
| Estimated Supply | About 6 to 12 weeks for one hot tub |
| Image Alt Text | Three yellow Spa Frog Serene 150 g bromine cartridges for FROG Serene Floating and In-Line systems, 3 pack |
How to Use the FROG Serene Bromine Cartridge
- Balance the water first: Test with FROG Test Strips 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 2 hours before retesting.
- Start up with FROG Jump Start: 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.
- Set both cartridges: 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.
- Snap them into the floater: 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.
- Fine-tune for a week: 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.
- Swap the yellow cartridge when empty: 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.
FROG Serene Bromine Cartridge Setting Chart
| Hot Tub Size | Bromine Cartridge Setting |
|---|---|
| 200 gallons | 0 |
| 250 gallons | 1 |
| 300 gallons | 1 |
| 350 gallons | 2 |
| 400 gallons | 3 |
| 450 gallons | 4 |
| 500 gallons | 5 |
| 550 gallons | 5 |
| 600 gallons | 6 |
From 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.
Compatibility Notes
Before You Buy
- This 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.
- In 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.
- It needs a blue FROG Serene Mineral Cartridge alongside it. FROG notes the lower bromine level only applies when FROG minerals are in use.
- Not for FROG @ease systems, which use SmartChlor chlorine cartridges instead of bromine.
- Sized 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.
- The cartridge holder or floater is not included. This listing is the replacement cartridge only.
Which FROG Serene Cartridge Do I Need?
| Cartridge | Made For | Replace |
|---|---|---|
| FROG Serene Mineral Cartridge (blue) | Serene Floating and Serene In-Line | Every 4 months, or at each drain and refill |
| FROG Serene Bromine Cartridge, 150 g (yellow) (this listing) | Serene Floating and Serene In-Line | When empty, about every 2 to 4 weeks |
| FROG Serene In-Line Bromine Cartridge, 200 g (green) | Mainly Serene In-Line (also fits Floating) | When empty, about every 2 to 4 weeks |
| FROG Serene Cartridge Kit (1 blue + 3 yellow) | Serene Floating or In-Line refill | One mineral cycle plus three bromine changes |
| FROG Serene In-Line Refill (1 blue + 1 green) | Serene In-Line refill | One mineral cycle plus one bromine change |
| FROG @ease cartridges | FROG @ease systems only | Separate SmartChlor system, not interchangeable with Serene |
Colors 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.
How Long Each Pack Lasts
| Pack | One Hot Tub, One Cartridge at a Time |
|---|---|
| 1 cartridge | 2–4 weeks |
| 3 Pack (this listing) | About 6–12 weeks |
| 6 Pack | About 3–6 months |
| 12 Pack | About 6–11 months |
Based 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.
Why Choose the Spa Frog Serene Bromine 3 Pack
Three genuine yellow cartridges keep your Serene floater supplied for roughly two to three months, so a fresh refill is always on hand when the current one empties. Shop the full FROG Serene line, or compare every hot tub bromine option at HotTubPirate.com.
Ideal For
- FROG Serene Floating and In-Line owners
- Keeping spares between orders
- Hot tubs from 200 to 600 gallons
- About two to three months of bromine
- Owners who test weekly
Frequently Asked Questions
How long will a 3 pack of FROG Serene bromine cartridges last?
Roughly six to twelve weeks for one hot tub, since FROG rates each cartridge at 2 to 4 weeks. Heavy use and bigger hot tubs land at the short end of that range.
Can I use these in a Hot Spring, Caldera or Marquis in-line system?
Yes, if the holder is a FROG Serene In-Line holder. FROG's catalog lists these yellow 150 g cartridges for the In-Line System. The green 200 g size also fits and holds more bromine.
Can I save money by refilling the cartridges?
No. FROG's label says not to refill them. The cartridge meters a set amount of bromine, so refilling with loose tablets can throw off the level and is not how it is registered for use.
How do I find the right dial setting for my hot tub size?
Look up your gallons on the FROG chart, from 0 at 200 gallons up to 6 at 600 gallons, and turn the cartridge to that number. Adjust by one setting a day until it reads 1.0 to 2.0 ppm.
Will a 3 pack get me to my next mineral change?
Sometimes. The mineral lasts 4 months, about 17 weeks. Three cartridges at 2 to 4 weeks each cover 6 to 12 weeks, so most hot tubs need one or two more before the mineral is due.
What makes a cartridge run out sooner?
FROG says cartridge life depends on hot tub size and the number of users. A higher setting, frequent soaks and many bathers all draw more bromine.
How do I put a new cartridge in the floater?
Set the cartridge to your number, then push it into its opening in the green FROG Serene floater until it stays in place, with the blue mineral cartridge in the other opening.
Which test strips should I use?
FROG Test Strips that read bromine, plus pH, alkalinity and hardness. FROG @ease strips are designed for SmartChlor systems, not Serene bromine.
Can I use these in a hot tub larger than 600 gallons?
The setting chart tops out at 600 gallons, and FROG lists the floating system for hot tubs of 150 to 600 gallons. For a larger spa, ask the HotTubPirate.com team about other options.
What is the lowest bromine level I should keep?
At least 1.0 ppm at all times, per FROG. The working range with FROG minerals is 1.0 to 2.0 ppm.
How often should I test when I first set up a cartridge?
Daily for the first week. FROG's manual says to adjust the cartridge one setting per day until the strip matches the 1.0 to 2.0 ppm bromine range, then test regularly after that.
Can I change the setting after the cartridge is in the floater?
Yes. Lift the floater out, turn the bromine cartridge up or down one number and put it back. FROG recommends one-step changes so you can see the effect the next day.
Will these work in a FROG @ease floating system?
No. FROG @ease runs on SmartChlor chlorine cartridges and its own mineral cartridge. Serene bromine cartridges are for FROG Serene systems.
What should I check if the water turns cloudy?
FROG's troubleshooting list: confirm pH, alkalinity and hardness, see whether the bromine cartridge is empty, make sure the mineral is under 4 months old and shock with FROG Maintain.
Are these the same cartridges as the single?
Yes. Each one is the standard yellow 150 g FROG Serene Bromine Cartridge, order code 01-14-3824. The 3 pack simply bundles three of them.
Safety Notes
Handle With Care
- Danger: 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.
- Do not open, break or refill the cartridge, and do not handle a damaged cartridge without protective gear.
- Strong oxidizer. Keep it away from heat, flames and combustible materials, and never mix it with other chemicals.
- Do not use it in a feeder or other device that has been used with calcium hypochlorite.
- If 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.
- Store 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.
Product Documents
Download 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.