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Best chlorine tablets for pools

Updated: 16.10.2026

You want a name, a price in pounds, and a reason to leave the other tubs in the basket. There is no lab winner among these amazon.co.uk listings, and the highest star line sits on a pack the page does not settle. This page on the best chlorine tablets for pools says who each kept listing is for, and who should skip it. Prices and scores for all seven are on the [chlorine tablets for pools](/hub/pool-care/chlorine-tablets-pool) comparison. The Products Compared editorial team used those listings and the review notes already in this set, as captured for 15 October 2026, plus UK Pool Store’s cyanuric acid sheet. A specialist shelf price is a second price, not a ranking.

You want a name, a price in pounds, and a reason to leave the other tubs in the basket. There is no lab winner among these amazon.co.uk listings, and the highest star line sits on a pack the page does not settle.

Our top picks

Relax Relax 5 kg multifunction tablets

Best overall

Relax Relax 5 kg multifunction tablets
8.8/10about £26.99
View offer
Deep Blue Deep Blue 5 kg 200 g multifunction tablets

Alternative

Deep Blue Deep Blue 5 kg 200 g multifunction tablets
8.1/10about £28.23
View offer
Deep Blue Deep Blue 5 kg 20 g multifunction tablets

Best value

Deep Blue Deep Blue 5 kg 20 g multifunction tablets
8.4/10about £21.98
View offer
On this page
  1. 1.There is no tested winner in this set
  2. 2.For a pool with a feeder you already have
  3. 3.For a hot tub, buy the 20 g tub
  4. 4.Stabilised tablets, and the kits to leave
  5. 5.A fit, not a lab winner

There is no tested winner in this set

Prefer a named chemistry, a pack whose title and weight agree, and a written review set, over a tenth of a star or a Chlorine best-seller rank. Deep Blue’s stabilised listing is 4.7 from 80 reviews at about £31.49, and the title still says 5 kg against a 1 kg unit count and model DBPCLTAB2002-1X1kg. That is the highest star line and the unresolved pack, so it is not a tested winner. The lowest shelf price is not a season of chlorine. SINPY is about £12.99 with 4.0 from 12 reviews. Bulla is rank 27 in Chlorine, with 3.8 from 25 reviews and complaints that the tablets do not dissolve. The criteria sit on the chlorine tablets buying guide.

For a pool with a feeder you already have

Relax is about £26.99 for 25 tablets of 200 g, also called 3 inch, in a 5 kg pack the listing agrees on. It is 4.6 from 264 reviews, the most in this set. The highlight names trichloroisocyanuric acid, and the bullets add stabiliser, algaecide and clarifier. The listing does not say skimmer, floater or feeder, and no floater is in the box. Deep Blue’s 200 g multifunction tub is the listing that names the place: a skimmer, a dosing chamber or a floater, at about £28.23 and 4.6 from 147 reviews. The title and the weight say 5 kg. The item-type name says 1 kg. One review warns against leaving tablets in the skimmer when the pump is off.
Relax Relax 5 kg multifunction tablets

Testsieger

Relax Relax 5 kg multifunction tablets
8.8/10about £26.99
View offer

For a hot tub, buy the 20 g tub

Deep Blue’s 20 g multifunction tub is about £21.98, and the title and the item weight say 5 kg. It is 4.6 from 130 reviews. The bullets state stabilised chlorine, a clarifier and an algaecide. The unit-count field says 1.0 count, and the listing does not name a feeder or a dose. Most of the reviews in the raw file are short praise from hot-tub users. One reviewer says the tablets last only two or three days. A 200 g puck is the wrong object here, even when the bucket is heavier. If the water is a paddling pool rather than a hot tub, use chlorine tablets for a small pool. The 20 g reviews are not a paddling-pool test.

Stabilised tablets, and the kits to leave

ChlorineXpress is about £24.99 for about 25 tablets of 200 g, and the title, the unit count and the weight agree on 5 kg. Cyanuric acid is named. It is not described as multifunction. There is no star line and no review text in the raw file, so it fits only if you will judge the first tub yourself. Deep Blue’s stabilised 200 g listing is 4.7 from 80 reviews at about £31.49. The bullets say it is not multifunction, so you dose algaecide and clarifier yourself, and only if you can live with not knowing whether the tub is 1 kg or 5 kg. The chemistry split is multifunction vs stabilised chlorine tablets.

A fit, not a lab winner

Relax is the top pick when you want a documented 200 g multifunction tub and you already have a feeder. Deep Blue’s 200 g multifunction tub is the one that names the feeder, once you check the 1 kg item-type line. The best value for a small tablet is the Deep Blue 20 g tub, for a hot tub. A qualifying purchase can earn a commission at no extra cost to you.

Common questions

Which tub has the most reviews?
Relax, at 4.6 from 264 amazon.co.uk reviews. Deep Blue’s 200 g multifunction tub is 4.6 from 147, and the 20 g tub is 4.6 from 130. The stabilised Deep Blue listing is 4.7 from 80, with the pack weight unresolved. Review count is not a lab score. The dust and crumble reviews stay attached to Relax.
Which is the cheap 5 kg tub if I want small tablets?
Deep Blue’s 20 g multifunction tub at about £21.98, where the title and the item weight both say 5 kg. It is 4.6 from 130 reviews, mostly from hot-tub users, and the unit count says 1.0 count. One review says the tablets last two or three days. It is a weak match if you need a 200 g puck for a pool feeder.
Is 4.7 from 80 better than 4.6 from 264?
Not here. A tenth of a star does not beat the larger written file, and the 4.7 line sits on the Deep Blue stabilised listing whose title says 5 kg while the weight and the model say 1 kg. Relax is 4.6 from 264, with trichloroisocyanuric acid named and an agreed 5 kg pack. Use 4.7 only if you can live with that conflict.
Which listing has no reviews at all?
ChlorineXpress. The raw file has no star line and no review text. The listing is about 25 tablets of 200 g at about £24.99, with title, unit count and weight all on 5 kg, and cyanuric acid named. It is not sold as multifunction. Consider it only if you will judge the first tub yourself. You cannot compare it on stars.
Can one of them be called the top pick?
You can call Relax the top pick for a documented 200 g multifunction tub: most reviews, trichloroisocyanuric acid named, and a 5 kg pack the listing agrees on. That is a fit, not a lab winner. The dust review and the missing feeder line stay in the same decision. If the feeder is the point, Deep Blue’s 200 g multifunction tub names one, and you still check the 1 kg item-type line.

Related pages

Algaecide or chlorine tablets

Chlorine tablets pool

Chlorine tablets buying guide: chemistry, size, weight

How to use chlorine tablets in a pool, step by step

Multifunction vs stabilised chlorine tablets compared

Chlorine tablets for a small pool or paddling pool

Sources

Public UK sources listed in the research digest. Listing prices, stars, and review counts are from the amazon.co.uk capture dated 15 October 2026, not a live re-check.

  1. HSE — Swimming pool safety management (retrieved 15 October 2026)
  2. HSE SR9 — Safe use of pool biocides (retrieved 15 October 2026)
  3. HSE — Biocides regulations (retrieved 15 October 2026)
  4. HSE — GB CLP classification and labelling (retrieved 15 October 2026)
  5. PWTAG Code of Practice (retrieved 15 October 2026)
  6. PWTAG TN68 — Handling and storage of pool chemicals (retrieved 15 October 2026)
  7. UK Pool Store — What is cyanuric acid (retrieved 15 October 2026)
  8. Swimming Pool Chemicals — Chlorine tablets (retrieved 15 October 2026)