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How to choose a pool flocculant

Updated: 21 October 2026

You have a cloudy garden pool, and amazon.co.uk has stacked cubes, liquids, cartridges and the word clarifier into one search. A pool flocculant sticks fine particles together so a sand or glass filter can catch them, or so they sink and you can vacuum them to waste. It is not a substitute for shock on a green pool, and it is not one bottle that suits every filter. This page is the decision order: filter, job, dose point, an English label, then any phosphate line. The [Flocculant pool comparison](/hub/pool-care/flocculant-pool) holds the nine listings we kept. A qualifying purchase can earn a commission at no extra cost to you. We did not run a lab test.

You have a cloudy garden pool, and amazon.co.uk has stacked cubes, liquids, cartridges and the word clarifier into one search.

Our top picks

Bayrol Bayrol Superflock Plus, 1 kg

Best overall

Bayrol Bayrol Superflock Plus, 1 kg
9.2/10about £22.02
View offer
Mineralsi Jolly Gel flocculent, 8 cubes

Alternative

Mineralsi Jolly Gel flocculent, 8 cubes
9.2/10about £24.99
View offer
Blue Horizons Blue Horizons granular floc, 2 kg

Alternative

Blue Horizons Blue Horizons granular floc, 2 kg
9.0/10about £18.91
View offer
On this page
  1. 1.What you are actually buying
  2. 2.Match it to the filter
  3. 3.Read the label before the price
  4. 4.What the shelf prices are for

What you are actually buying

Three patterns cover the products that stayed in the comparison. A drop floc settles debris so you vacuum it to waste. Blue Horizons granular floc, 2 kg at about £18.91, is limited to sand filters. HTH rapidfloc, 3 litres at about £23.32, never names a filter. A filter-aid cartridge sits in the skimmer, then you backwash. Bayrol Superflock Plus and HTH Regularfloc are that job. A gel cube, Jolly Gel, goes in the pump basket. If a title mixes the words, the flocculant versus clarifier page is the fork. Nortembio at about £11.95 says the filter catches particles and that they settle. Those are two routines. Quickflock Super, about £20.50, says 100–200 ml over the skimmer, then 15 minutes. Bayrol's Quickflock liquid page doses upstream of the filter and says not to pour that liquid into the pool. A weekly sock is not an overnight rescue.

Match it to the filter

Sand or glass with a waste line can take a drop floc or a skimmer cartridge. Cartridge, diatomaceous-earth and fibre-ball filters are the wrong media for Jolly Gel and for sand-only granules. PoolPro aims liquid clarifiers at cartridge filters and jelly or tablet flocculants at sand. Magnum Filters says most flocs can affect a cartridge warranty unless you can send water to waste. Blue Horizons prints sand only, pre-dissolve at most 100 g per 10 litres, then vacuum to waste. Regularfloc is 10 cartridges for a sand filter, about £22.84. Jolly Gel's maker in East Sussex prints the pump basket on sand, glass or zeolite. A UK review of the unnamed cubes says fibre balls stopped until they were washed. Read the flocculant for a sand filter note if that is your media. Bayrol's sheet, when the amazon line is thinner, says sand or glass, not cartridges, one cartridge up to 50 m³.
Bayrol Bayrol Superflock Plus, 1 kg

Testsieger

Bayrol Bayrol Superflock Plus, 1 kg
9.2/10about £22.02
View offer

Read the label before the price

English instructions sit inside a safe product under the General Product Safety Regulations 2005, and GB CLP expects English hazard labels in Great Britain. Several UK reviews of Quickflock Super say the bottle had no English instructions. A 4.3 rating from 1,586 reviews does not fill that gap when the parcel arrives. Pack size is the next trap. One reviewer said the Blue Horizons tub was about 1.5 kg, not 2 kg. Nortembio prints 240 g and 340 g. The about £47.78 Superflock Plus title says 1 kg and also prints 29.57 ml. Jolly Gel's maker prints both up to 12,500 gallons and 20–60 m³. Buy the figure you can check on the parcel.

What the shelf prices are for

On 19 October 2026 these nine ASINs sat in three bands, not a national average. Entry was about £11.95 to about £18.91. Mid was about £20.50 to about £24.99. The other Superflock Plus 1 kg listing was about £47.78. The best pool flocculant page is for a vacuum rescue, a weekly sock or a gel cube. If you cannot send water to waste and the label is a drop floc, leave it on the shelf.

Common questions

Can I use pool flocculant with a cartridge or fibre-ball filter?
Not the products in this comparison. Blue Horizons prints sand only. Jolly Gel's maker excludes cartridge and diatomaceous-earth filters. Superflock Plus's sheet is sand or glass, not cartridges. A UK review of the unnamed cubes said fibre-ball filters stopped until they were washed. Intex says flocculant clogs its cartridge pumps. With no waste line, a drop floc has nowhere safe to go.
Does “removes phosphates” apply to every listing?
No. Only some lines say it. Jolly Gel claims phosphate removal, and one UK indoor-pool reviewer still recorded about 3,000 while dosing cubes about every two weeks. Superflock Plus's data sheet names lanthanum(III) chloride hydrate and aluminium sulfate, a composition, not a percentage removed. Blue Horizons, HTH rapidfloc and the unnamed cubes state no phosphate claim in the fields we used.
Why are there two Superflock Plus listings at about £22.02 and about £47.78?
Both titles say 1 kg. About £22.02 says place the cartridge in the skimmer, 4.6 from 4,576 reviews, and is the best value of the two. About £47.78 also prints 29.57 ml. Its first 50 written reviews are marked Germany. Compare the pack photo before you pay more.
What if the bottle has no English instructions?
Several UK reviews of Quickflock Super say the bottle had none. You then cannot check the dose against Bayrol's other Quickflock page, which is a different routine. GB CLP expects English hazard text in Great Britain. If the parcel has no English sequence, do not guess a millilitre dose. Use a listing you can read, or contact the seller before it goes near the water.
Should I buy before I can see the deep end?
No. If you cannot see the deep-end floor, stay out. East Lindsey says keep a small pool closed when the deep end is not clearly visible. PWTAG's cloudy-water note, for managed pools, uses a clear view of the deepest bottom and 0.5 NTU as a guideline. Domestic pools sit outside that code. Shock and balance come before you judge a floc.

Related pages

How to use pool flocculant

Flocculant pool

Best pool flocculant UK: vacuum, weekly sock or cube

Flocculant for a sand filter: what the listings say

Flocculant vs clarifier: which bottle for the pool

Sources

Public UK and maker sources used for this page in October 2026. Shelf prices and star lines are the amazon.co.uk figures for these nine listings, dated 19 October 2026.

  1. HSE: Swimming pools (retrieved 21 October 2026)
  2. HSE: GB CLP (retrieved 21 October 2026)
  3. PWTAG: Cloudy water technical note (retrieved 21 October 2026)
  4. PWTAG: Code of Practice (retrieved 21 October 2026)
  5. East Lindsey: Small swimming pools guidance (retrieved 21 October 2026)
  6. Bayrol: Superflock Plus data sheet (retrieved 21 October 2026)
  7. Bayrol: Quickflock liquid (retrieved 21 October 2026)
  8. Jolly Gel, Mineral Supplies International (retrieved 21 October 2026)