Pool Extra-Strength Algaecide - Copper Sulphate Blend

Quaternary ammonium pool algaecide for fast knock-down of green algae blooms. Concentrated formula clears visible algae within 24-48 hours when paired with a chlorine shock.

• Knocks down active green algae blooms within 24-48 hours.
• Pairs with chlorine shock for stubborn black or yellow algae.
• High-concentrate formula needs only 50 ml per 10 m³ to dose.
• Cheaper per dose than polyquat for active treatment.
• Compatible with all pool surface types.

Sizes and prices

• 5L: £38.00
• 10L: £72.25
• 25L: £175.00

When you need it

• You can see active green algae on walls, steps or in corners.
• Pool has gone cloudy green overnight after a heatwave.
• Long-life algaecide alone has not cleared a bloom.
• Polyquat dose has been missed and bloom is starting.
• You need a fast knock-down before guests arrive.

How to use

1. Brush all visible algae loose from walls and floors.
2. Shock pool to 10 ppm with cal-hypo first.
3. Wait 4 hours, then dose 50 ml per 10 m³ of algaecide.
4. Pre-dilute in 10 L bucket of pool water; pour around perimeter.
5. Run filtration continuously for 24 hours.
6. Vacuum dead algae to waste, not back through filter.

Dosing guide

Use as a treatment, not a routine preventer. After bloom clears, switch back to polyquat long-life for prevention.

• For 20 m³, add 100 ml to reach Treatment dose.
• For 40 m³, add 200 ml to reach Treatment dose.
• For 60 m³, add 300 ml to reach Treatment dose.
• For 100 m³, add 500 ml to reach Treatment dose.
• For 40 m³, add Repeat 200 ml to reach Heavy bloom (24h follow-up).

How it works

Alkyl dimethyl benzyl ammonium chloride (benzalkonium chloride) at 50% w/w, the standard quaternary ammonium algaecide used for fast bloom clearance.

The cationic surfactant disrupts algal cell membranes by displacing the cell's own surface lipids. Algae lose membrane integrity within hours and detach from surfaces for vacuuming.

Polyquat prevents; quat treats. When a bloom is already visible, polyquat alone is too slow. A short concentrated quat dose paired with chlorine shock is the fastest legitimate way to clear water.

Frequently asked questions

Do I shock first?

Yes. Shock to 10 ppm chlorine, wait 4 hours, then dose algaecide. Algaecide alone will not clear a heavy bloom.

How much per m³?

5 ml per m³ for treatment. For a 40 m³ pool that is 200 ml.

Can I use this every week?

No. This is a treatment, not a preventer. Switch to polyquat long-life for routine cover.

Pack sizes?

1 L, 5 L drums.

Will it foam?

Yes under aerated jets. Switch features off during treatment; switch to polyquat for routine.

Is it cheaper than polyquat?

Per ml of concentrate yes; per dose for routine prevention no, because quat doses come more often.

What is the active ingredient?

Alkyl dimethyl benzyl ammonium chloride at 50% w/w.

Why does it foam?

Quaternary ammonium chains are surfactants; they create stable foam under air entrainment.

Does it consume chlorine?

Slightly, around 1 ppm per 100 ml in 40 m³. Top up chlorine after dosing.

Bloom not clearing?

Re-shock to 15-20 ppm; brush more; vacuum dead algae to waste.

Foaming?

Switch off jets; switch to polyquat for next maintenance dose.

Quat vs polyquat?

Quat is fast and cheap for treatment; polyquat is non-foaming and long-lasting for prevention. Use both, in their respective jobs.

Quat vs copper-based?

Quat is staining-safe but foams; copper kills tougher algae but stains plaster and hair. Polyquat sits between for prevention.