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

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.

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.

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.

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

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

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.

Pool Extra-Strength Algaecide - Copper Sulphate Blend

Name: Pool Extra-Strength Algaecide - Copper Sulphate Blend
Brand: ClearSpa
SKU: pa-2
Availability: InStock
Rating: 4.5 (5 reviews)

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.