A vented ball that meters a tablet, and keeps it off the liner

The best chlorine dosing floats for 2026

A dosing float is a vented plastic ball holding a chlorine or bromine tablet, and it does two jobs that are easy to underestimate. It meters — the vents set how much water reaches the tablet, which sets the dissolution rate — and it keeps the tablet off the liner, which is the difference between a chlorinated pool and a bleached patch of vinyl. The first specification is the tablet capacity and size, and it is a compatibility question: a floater built for 20 g tablets will not take a 200 g puck, and a floater built for 200 g pucks meters a 20 g tablet far too fast. The second is the vent adjustment, which is the entire control the device offers; a fixed-vent floater cannot be turned down for a cool week or a small bather load. Then the material, because this object lives in the most aggressive water in the pool — its inside is in contact with an undissolved tablet — and the ones that survive several seasons say what they are made of. Weighted or tethered designs matter more than they look: an untethered floater drifts into the skimmer, where it doses the filter rather than the pool, and a floater that ends up stuck against a wall bleaches a stripe. And spa suitability, which is a separate question because spa floaters are smaller, slower and generally meant to be removed while bathing. We compare tablet size and capacity, vent adjustment, materials, tether or weight and spa versions.

These parts, one figure beside another

1. 

   Bestway Dosierschwimmer Ø 12,5 cm

   A 12.5 cm float taking tablets up to Ø 2.5 cm with an adjustable dosing aperture — the smallest tablet ceiling published on this shelf.

   Tablet size

   Tablets up to Ø 2.5 cm — the smallest ceiling in this family. The 20 g chlorine tablets in this catalogue are published at about Ø 3 cm

   Capacity

   Not published as a weight. Float diameter Ø 12.5 cm

   Vent adjustment

   Adjustable dosing aperture, stated

   Materials

   Not published

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Not published

   Amazon reference

   B0CDXMDW7C (one reference across 6 Amazon marketplaces)

   EAN

   6941607347416

   • Publishes a tablet diameter rather than only a weight, which is what actually has to fit
   • An adjustable aperture, which six of the seven floats here have
   • Ø 2.5 cm excludes the 20 g tablets published in this catalogue at about Ø 3 cm

   Best for: Small tablets of 2.5 cm or less, in a Bestway pool

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2. 

   wojonifuiliy Dosierschwimmer 20 g

   A 20 g float in chemical-resistant PVC with an adjustable ring at the base, stated for chlorine or bromine tablets and for a pool, a spa or a garden fountain.

   Tablet size

   Not published as a diameter. Capacity 20 g of chlorine or bromine tablets

   Capacity

   Up to 20 grams

   Vent adjustment

   Adjustable ring at the base controlling the release rate, stated to be matched to water volume, water temperature and current water quality

   Materials

   PVC, blue and white, stated chemical-resistant and to withstand ageing, cracking and fading under permanent sun and water exposure, with a smooth surface resisting scale and algae

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Not published as a separate version. Stated for pools, hot tubs, spas, water parks, fish ponds and garden fountains

   Amazon reference

   B0GY3WCTX6 (one reference across 5 Amazon marketplaces)

   EAN

   0762809742993

   • The most detailed material statement here — PVC, named, with four specific resistances
   • States what the ring should be set against: volume, temperature and current water quality
   • No tablet diameter, so fit against a 3 cm tablet cannot be checked

   Best for: A small pool or spa dosed with 20 g tablets, where the release rate is adjusted through the season

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3. 

   Intex Chlorspender 29044

   A floating dispenser for Intex inflatable spas and PureSpas up to 1 098 litres, taking a single 3.8 cm chlorine tablet — the largest published tablet diameter on this shelf.

   Tablet size

   One tablet of 3.8 cm — the largest tablet diameter published in this family

   Capacity

   One tablet

   Vent adjustment

   Not published — the only float in this family without an adjustable ring

   Materials

   Plastic, brown. No polymer named

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Yes — stated for Intex inflatable hot tubs and PureSpas up to 1 098 litres. The only float here sized to a stated water volume

   Amazon reference

   B07KWRGJZY (one reference across 6 Amazon marketplaces)

   EAN

   6941057413983

   • The only float here matched to a published water volume — up to 1 098 litres
   • Publishes the tablet diameter it takes, which five rivals do not
   • No adjustable aperture — the only float in this family without one

   Best for: An Intex PureSpa or inflatable hot tub under 1 098 litres

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4. 

   FUDUOXIAO Dosierschwimmer 7 Inch

   A seven-inch float in PP with an adjustable base ring and an extendable body that collapses for storage — the only telescoping dispenser on this shelf.

   Tablet size

   Not published

   Capacity

   Not published as a weight. Float diameter 7 inch — about 17.8 cm, the largest in this family

   Vent adjustment

   Adjustable ring at the base for precise control of the dosing quantity, stated

   Materials

   PP, stated light, with high buoyancy, safe, environmentally friendly and durable, with a smooth surface resisting dirt build-up and no ageing or cracking after long immersion

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Not published as a separate version. Stated for pools, water parks, wellness centres, aquariums, fish ponds and garden fountains

   Amazon reference

   B0GZNR2BLS (one reference across 5 Amazon marketplaces)

   EAN

   0760314812736

   • The only float here that collapses for storage and transport
   • The largest float body on this shelf at seven inches
   • Publishes neither a tablet size nor a capacity in grams

   Best for: A larger pool where the dispenser is put away between seasons

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5. 

   HAF Dosierschwimmer 20 g

   A 20 g float for chlorine or bromine tablets with a regulated dosing aperture, stated to distribute evenly without direct tablet contact with the pool.

   Tablet size

   Not published as a diameter. Suitable for 20 g chlorine tablets, stated

   Capacity

   20 g

   Vent adjustment

   Regulated dosing aperture allowing individual setting, so the chlorine supply can be matched to pool size, use and temperature, stated

   Materials

   Not published as a polymer. Stated robust and resistant to pool chemistry, UV radiation and water

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Not published as a separate version. Stated for above-ground and garden pools, swimming pools and hot tubs

   Amazon reference

   B0D1NDYBKJ (one reference across 1 Amazon marketplace)

   EAN

   4262465963696

   • Names three things the aperture should be matched to: pool size, use and temperature
   • States the point of a float plainly — no direct contact between tablet and pool
   • No tablet diameter published, only a weight

   Best for: An above-ground pool dosed with 20 g tablets, chlorine or bromine

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6. 

   Gre Dosierer 40070 with thermometer

   The widest tablet range on this shelf — 20 to 500 g — with a built-in thermometer and a product consumption indicator, so one object does three jobs.

   Tablet size

   Not published as a diameter. For tablets from 20 to 500 g — the widest range in this family

   Capacity

   Up to 500 g

   Vent adjustment

   Lower ring regulating the dissolution of the chemicals at higher or lower intensity, stated

   Materials

   Highly resistant thermoplastic, stated durable and resistant. No polymer named

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Not published. Includes an indicative thermometer containing alcohol and phenol red, and a product consumption indicator

   Amazon reference

   B00L2IG7AG (one reference across 6 Amazon marketplaces)

   EAN

   8427370400704

   • The widest tablet range on this shelf — 20 g to 500 g covers both tablet sizes in this catalogue
   • A built-in thermometer, so one fewer object floats in the pool
   • No tablet diameter, only a weight range

   Best for: A pool using 200 g tablets, where the water temperature is worth watching

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7. 

   Monzana Dosierschwimmer 20–200 g set

   A large float taking both 20 g and 200 g tablets — chlorine, salt, oxygen or bromine — supplied with 150 three-in-one test strips and a thermometer.

   Tablet size

   Not published as a diameter. For 20 g and 200 g tablets — chlorine, salt, oxygen or bromine

   Capacity

   20 g to 200 g

   Vent adjustment

   Adjustment ring for individual and even release of the pool chemistry, stated

   Materials

   Robust UV-resistant PVC, stated durable, colour-stable and gentle on the pool liner, with an edge-free surface

   Tether or weight

   Not published — as with all seven floats in this family

   Spa version

   Not published as a separate version. Stated for paddling pools, hot tubs, above-ground and frame pools and swimming ponds. Supplied with 150 3-in-1 test strips and a thermometer

   Amazon reference

   B0H2N4MLK9 (one reference across 5 Amazon marketplaces)

   EAN

   4251776937502

   • Takes both tablet sizes sold in this catalogue, and names four chemistries
   • States that the extra-large opening does not open by itself, which no other listing addresses
   • No tablet diameter published

   Best for: A frame pool or swimming pond where both tablet sizes might be used and the water is tested weekly

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