Twenty grams or two hundred, and a stabiliser that accumulates

The best chlorine tablets for 2026

Chlorine tablets are the default way a private pool is disinfected, and three things on the label decide what you are buying. The first is the tablet weight: 20 g tablets are for spas, small pools and floating dispensers; 200 g tablets are for skimmers and larger volumes, and the two are not a preference — a 200 g tablet in a 4 000-litre pool overshoots badly. The second is the active chlorine content, and this is where prices stop being comparable: slow-dissolving tablets are usually trichlor at around 90 % available chlorine, and the cheaper products are dichlor or a blend at 56 % or less. Paying less per kilogram for a 56 % product is paying more per gram of chlorine. The third is the thing that catches out every pool in its third season: stabiliser. Trichlor carries cyanuric acid, which protects chlorine from UV and is why the tablets work outdoors at all — and which does not evaporate, does not break down and accumulates every time a tablet dissolves. Above roughly 75–100 mg/l the chlorine present stops acting, the test still reads chlorine, and the only remedy is dilution. Then the multifunction claims — 3-in-1, 5-in-1, adding algicide, clarifier and hardness stabiliser — which are convenient and which remove the ability to dose one thing without the others. We compare tablet weight, active content and chemistry, dissolving speed, stabiliser load and multifunction contents.

These parts, one figure beside another

1. 

   Medfuture Multitabs 11 in 1 Blue, 20 g

   The longest function list on this shelf: eleven, on 20 g slow-dissolving tablets in a 1 kg resealable tub of about fifty. No dose is published.

   Tablet weight

   20 g. About 50 tablets in a 1 kg tub

   Active content

   Not published

   Chemistry

   Not published. BAuA notification number N-117138, stated

   Dissolving speed

   Slow-dissolving, with even release of active ingredients over several days, stated

   Stabiliser load

   Not published. pH stabilisation is named among the functions

   Multifunction contents

   11: disinfection, algae prevention, flocculation, pH stabilisation, scale protection, cloudiness removal, metal binding, foam prevention, and more — the listing names nine and says more

   Amazon reference

   B0F6TLCSCQ (one reference across 1 Amazon marketplace)

   EAN

   5905316223295

   • The longest published function list in this family — eleven
   • A resealable tub rather than a sack, on a product that must stay dry
   • No dose published at all, on a product with eleven claimed functions

   Best for: A small pool or hot tub where a resealable tub of small tablets suits the volume

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2. 

   STEINBACH Chlortabs 200 g, 1 kg

   Plain slow-dissolving 200 g chlorine tablets with no added functions — the only single-purpose tablet on this shelf — stated pH-neutral, lime-free and dissolving without residue.

   Tablet weight

   200 g. Pack size 1 kg

   Active content

   Not published

   Chemistry

   Not published. Stated pH-neutral and lime-free. BAuA registration number N-86777

   Dissolving speed

   Slow-dissolving, developed for continuous disinfection, stated. Dissolves without residue and does not clog filters or dosing systems

   Stabiliser load

   Not published

   Multifunction contents

   None — a single-function chlorine tablet. The only one in this family without added functions

   Amazon reference

   B01N07Q5JX (one reference across 2 Amazon marketplaces)

   EAN

   9008748008396

   • The only plain chlorine tablet on this shelf, so nothing is added that is not wanted
   • Stated to dissolve without residue and not to clog filters or dosing systems
   • No active chlorine content and no chemistry published

   Best for: A pool already balanced with separate products, where the tablet should only chlorinate

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3. 

   BlueViking 5 in 1 Multitabs 20 g, 1 kg

   The only tablet in this family to publish an active chlorine content — a stated minimum of 86 % — on 20 g 5-in-1 tablets dosed at one per 2 m³ into the skimmer.

   Tablet weight

   20 g. Pack size 1 kg

   Active content

   Minimum 86 % active chlorine — the only active content published in this family

   Chemistry

   Not published as a compound. Approved under EU Biocidal Products Regulation 528/2012/EC, BAuA N-106206, stated

   Dissolving speed

   Slow and even dissolution, releasing chlorine constantly, stated

   Stabiliser load

   Not published as a quantity. A chlorine stabiliser is named among the five functions

   Multifunction contents

   5: algaecide, bactericide, flocculant, chlorine stabiliser and pH regulator

   Amazon reference

   B0CKXHZGSJ (one reference across 1 Amazon marketplace)

   EAN

   4262360810224

   • The only tablet here to publish an active chlorine content — minimum 86 %
   • Publishes a dose: one tablet per 2 m³ into the skimmer
   • No chemistry named, so the compound behind the 86 % is unstated

   Best for: A small to mid-sized pool where the buyer wants a published active content behind the tablet

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4. 

   BELKO Chlor MultiTabs 5 in 1, 20 g

   Five-kilogram pack of 20 g 5-in-1 tablets, published at ø 3 cm × 2 cm high, dosed at one tablet per 2.5 m³ per week for pools up to 20 m³.

   Tablet weight

   20 g, ø about 3 cm and about 2 cm high — the only tablet dimensions published in this family. Pack size 5 kg

   Active content

   Not published

   Chemistry

   Not published. Biocide registration number N-113447, stated

   Dissolving speed

   Slow-dissolving, for continuous disinfection, stated

   Stabiliser load

   Not published as a quantity. A hardness stabiliser is named among the functions

   Multifunction contents

   5: pH stabilisation, flocculation, algae prevention, clarifying effect and continuous disinfection. Stated for pools up to 20 m³

   Amazon reference

   B0H3VYS869 (one reference across 1 Amazon marketplace)

   EAN

   4062833050849

   • The only listing here to publish the tablet’s physical dimensions — ø 3 cm × 2 cm
   • Publishes a dose with an interval: one 20 g tablet per 2.5 m³ per week
   • No active chlorine content, where one tablet in this family publishes 86 %

   Best for: A pool up to 20 m³ dosed weekly through a float, where the pack should last more than one season

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5. 

   Fresh-Pool Profi Langzeit Chlortabletten 200 g

   Individually sealed 200 g stabilised chlorine tablets in a 5 kg pack, stated slow-dissolving, pH-neutral and independent of water hardness.

   Tablet weight

   200 g, individually sealed. Pack size 5 kg

   Active content

   Not published. Stated stabilised chlorine with active chlorine

   Chemistry

   Not published as a compound. Stated stabilised chlorine, pH-neutral. Biocide registration number N-113036

   Dissolving speed

   Slowly soluble, independent of water hardness, stated, with stabilisation against rapid chlorine breakdown

   Stabiliser load

   Not published as a quantity. Stabilising against rapid chlorine breakdown is stated

   Multifunction contents

   Not stated as a numbered multifunction tablet. Disinfection and long action are the published functions

   Amazon reference

   B0CYT7KDJ6 (one reference across 1 Amazon marketplace)

   EAN

   4038755070555

   • Individually sealed tablets, which keeps the rest of the pack dry once one is used
   • Stated independent of water hardness, so the dose does not change with the supply
   • No dose published, on a 200 g tablet where the pool volume decides everything

   Best for: A pool dosed at intervals, where the pack must survive between uses

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6. 

   Höfer Chemie BAYZID Multitabs 5 in 1, 200 g

   A 5 kg pack of 200 g 5-in-1 tablets, and one of only two on this shelf to name its chemistry: an organic chlorine product stabilised with cyanuric acid, stated free of boric acid.

   Tablet weight

   200 g. Pack size 5 kg

   Active content

   Not published

   Chemistry

   An organic chlorine product stabilised with cyanuric acid, stated — one of two chemistry statements in this family. Stated free of harmful boric acid. Biocide registration number N-63988

   Dissolving speed

   Long-term treatment, stated. No dissolution rate published

   Stabiliser load

   Cyanuric acid named as the stabiliser. No quantity published

   Multifunction contents

   5: pH regulation, water disinfection, algae control, flocculation and scale prevention

   Amazon reference

   B008RV6UY4 (one reference across 3 Amazon marketplaces)

   EAN

   4250463105491

   • Names its chemistry — organic chlorine stabilised with cyanuric acid — which five rivals here do not
   • States what it is free of: boric acid
   • No dose published, on a 200 g tablet

   Best for: A pool already balanced, kept there through the season on a stabilised multifunction tablet

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7. 

   Bayrol e-Chlorilong Ultimate 7

   A two-layer 7-in-1 tablet — a blue layer for immediate shock chlorination and a white layer for continuous disinfection — with the fullest dosing instruction on this shelf.

   Tablet weight

   Not published as a weight. Dosed as one tablet per 20 to 30 m³

   Active content

   Not published

   Chemistry

   Not published as a compound. Stated without copper sulphate and without boric acid. BAuA registration number N-85672

   Dissolving speed

   Two-phase: the blue layer gives immediate shock chlorination of water and filter, the white soluble layer gives lasting disinfection. One tablet every 7 to 10 days

   Stabiliser load

   Not published as a quantity. Chlorine stabilisation is named among the seven functions

   Multifunction contents

   7: disinfection, algae prevention, flocculation, scale prevention, chlorine stabilisation, plus shock treatment of pool water and of the filter

   Amazon reference

   B083WCWHXR (one reference across 4 Amazon marketplaces)

   EAN

   4008367993542

   • The fullest dosing instruction in this family — volume, interval, circulation time, pH range and filter preparation
   • A two-layer construction with a stated purpose for each layer
   • No tablet weight published, so the dose cannot be converted to grams per cubic metre

   Best for: A pool of 20 to 30 m³ on a weekly routine, where the filter is treated along with the water

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