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Lo-Chlor Algae Knock-out 2.5 L

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Lo-Chlor Algae Knock-out 2.5 L

Lo-Chlor Chemicals
Emergency strengthGreen pool rescue
Fast-actingResults within 24hrs
100% Aus madeOwned & operated
Lo-Chlor is Australia's most trusted specialist pool and spa chemical manufacturer globally recognised and exporting to 25+ countries. Their range covers algaecides, clarifiers, phosphate removers, stain treatments, stabilisers, spa care, equipment aids and more, every product formulated for Australian water chemistry and climate.
Lo-Chlor — Algaecides
Algae Knock-Out
⚡ Emergency strength Green pool rescue Fast-acting All pool types
📋 How it works▾

Lo-Chlor Algae Knock-Out is the highest-strength copper algaecide in the Lo-Chlor range — formulated for green pool emergencies when standard algaecide hasn't kept pace with the algae. The 2.5L bottle treats pools up to 125,000L at the standard dose — the right size for a single emergency treatment of most residential pools.

When a pool turns green, the algae population has overtaken the preventative dosing level. Knock-Out's concentrated formula delivers a rapid, high-impact dose that kills algae quickly — then follow up with a clarifier and preventative algaecide to restore and maintain water clarity.

Lo-Chlor Algae Knock-Out details

  • Highest-strength copper algaecide in the Lo-Chlor range
  • Designed for emergency green pool treatment, not routine prevention
  • This 2.5L bottle treats pools up to 125,000L at standard emergency dose
  • Kills green, black and mustard algae rapidly
  • Compatible with all pool surfaces and sanitiser systems
  • Always super-chlorinate before applying Knock-Out for fastest results

For routine prevention once the pool is clear, switch to Lo-Chlor Pool Algaecide or Lo-Chlor Tropiclear for heated pools. After Knock-Out treatment, dose Lo-Chlor Miraclear Liquid Clarifier to clear the dead algae from suspension. If algae keeps returning, the root cause is likely elevated phosphates — treat with Lo-Chlor Starver X.

🔍 Does it suit my pool?▾

Select your pool type to confirm this product suits your setup.

🧂Salt chlorinated▾
✓ Compatible — recommended for salt pools
Algae Knock-Out works with all chlorine-based systems including salt chlorinators. Salt pools are more vulnerable during low-chemical periods as chlorinators may run reduced hours. A dose of Algae Knock-Out provides a backup defence that doesn't rely on your chlorinator.
💧Traditional chlorine▾
✓ Compatible — ideal for chlorine pools
Algae Knock-Out is fully compatible with all traditional chlorine systems. Add it separately from chlorine shock, and allow at least 2 hours between additions.
🪨Mineral / magnesium▾
✓ Compatible — works with all mineral systems
Algae Knock-Out is safe for mineral and magnesium pool systems. It works independently of your sanitiser chemistry.
⚡Ionised / Nature2▾
⚠ Use with care — consider metal-free alternative
Algae Knock-Out contains copper compounds. Ionised pools (Nature2, Zodiac mineral) already introduce copper ions — additional copper can cause staining at low pH. We recommend Lo-Chlor Miraclear Metal-Free Algaecide for ionised pool setups.
🏊Fibreglass▾
✓ Compatible — safe for fibreglass
Algae Knock-Out is safe for fibreglass surfaces at recommended doses. Ensure pH is balanced (7.2–7.6) before adding to avoid any colour sensitivity.
🧱Concrete / pebblecrete▾
✓ Compatible — particularly effective on pebblecrete
Copper-based algaecides are especially effective against black spot algae, which is most common in pebblecrete and concrete pools. Use at the higher end of the dosage range for black spot prevention.
💊 Dosage guide▾

All doses are per 50,000L of pool water. Always super-chlorinate first and allow 2 hours before adding Knock-Out.

🟡 Mildly green pool
200 ml
per 50,000 L
Slight green tinge, still partially visible. Shock with chlorine first.
🟢 Clearly green pool
400 ml
per 50,000 L
Green water, bottom not clearly visible. Full treatment dose. Run filter continuously for 48 hours.
⬛ Dark green / black pool
600 ml
per 50,000 L
Heavy infestation. May require second application at 48 hours. Backwash filter before repeating.
🔄 Follow-up after treatment
After Knock-Out clears algae, dead particles remain suspended. Add clarifier 24 hours later to restore sparkle.
❓ FAQ▾
When should I use Knock-Out vs Pool Algaecide?▾
Use Lo-Chlor Pool Algaecide for routine prevention — monthly dosing keeps algae from establishing. Use Algae Knock-Out when you've already got a green pool emergency. After Knock-Out rescues the pool, switch back to Pool Algaecide for ongoing prevention.
My pool is still green after one dose. What next?▾
Allow 48 hours and run the filter continuously. If still green, backwash the filter — a clogged filter can't clear dead algae — then apply a second dose. Also check phosphate levels with the Starver Test Kit — high phosphates allow algae to regrow faster than treatment can keep up.
Will Knock-Out work in a heavily cloudy pool?▾
Yes — but super-chlorinating first is important. Organic matter in very dirty water consumes chlorine rapidly. Shocking first clears the organic load so Knock-Out can target the algae directly.
Do I need to do anything after the algae is killed?▾
Yes — dead algae turns the water grey-green and remains suspended in the water column. Dose Lo-Chlor Miraclear Liquid Clarifier 24 hours after the algae is dead to coagulate the particles and clear the water. Run the filter continuously and backwash once the water starts to clear.
$20.94
Lo-Chlor Algae Knock-out 2.5 L—
$20.94

Product Information

Shipping & Returns

Description

Lo-Chlor Chemicals
Emergency strengthGreen pool rescue
Fast-actingResults within 24hrs
100% Aus madeOwned & operated
Lo-Chlor is Australia's most trusted specialist pool and spa chemical manufacturer globally recognised and exporting to 25+ countries. Their range covers algaecides, clarifiers, phosphate removers, stain treatments, stabilisers, spa care, equipment aids and more, every product formulated for Australian water chemistry and climate.
Lo-Chlor — Algaecides
Algae Knock-Out
⚡ Emergency strength Green pool rescue Fast-acting All pool types
📋 How it works▾

Lo-Chlor Algae Knock-Out is the highest-strength copper algaecide in the Lo-Chlor range — formulated for green pool emergencies when standard algaecide hasn't kept pace with the algae. The 2.5L bottle treats pools up to 125,000L at the standard dose — the right size for a single emergency treatment of most residential pools.

When a pool turns green, the algae population has overtaken the preventative dosing level. Knock-Out's concentrated formula delivers a rapid, high-impact dose that kills algae quickly — then follow up with a clarifier and preventative algaecide to restore and maintain water clarity.

Lo-Chlor Algae Knock-Out details

  • Highest-strength copper algaecide in the Lo-Chlor range
  • Designed for emergency green pool treatment, not routine prevention
  • This 2.5L bottle treats pools up to 125,000L at standard emergency dose
  • Kills green, black and mustard algae rapidly
  • Compatible with all pool surfaces and sanitiser systems
  • Always super-chlorinate before applying Knock-Out for fastest results

For routine prevention once the pool is clear, switch to Lo-Chlor Pool Algaecide or Lo-Chlor Tropiclear for heated pools. After Knock-Out treatment, dose Lo-Chlor Miraclear Liquid Clarifier to clear the dead algae from suspension. If algae keeps returning, the root cause is likely elevated phosphates — treat with Lo-Chlor Starver X.

🔍 Does it suit my pool?▾

Select your pool type to confirm this product suits your setup.

🧂Salt chlorinated▾
✓ Compatible — recommended for salt pools
Algae Knock-Out works with all chlorine-based systems including salt chlorinators. Salt pools are more vulnerable during low-chemical periods as chlorinators may run reduced hours. A dose of Algae Knock-Out provides a backup defence that doesn't rely on your chlorinator.
💧Traditional chlorine▾
✓ Compatible — ideal for chlorine pools
Algae Knock-Out is fully compatible with all traditional chlorine systems. Add it separately from chlorine shock, and allow at least 2 hours between additions.
🪨Mineral / magnesium▾
✓ Compatible — works with all mineral systems
Algae Knock-Out is safe for mineral and magnesium pool systems. It works independently of your sanitiser chemistry.
⚡Ionised / Nature2▾
⚠ Use with care — consider metal-free alternative
Algae Knock-Out contains copper compounds. Ionised pools (Nature2, Zodiac mineral) already introduce copper ions — additional copper can cause staining at low pH. We recommend Lo-Chlor Miraclear Metal-Free Algaecide for ionised pool setups.
🏊Fibreglass▾
✓ Compatible — safe for fibreglass
Algae Knock-Out is safe for fibreglass surfaces at recommended doses. Ensure pH is balanced (7.2–7.6) before adding to avoid any colour sensitivity.
🧱Concrete / pebblecrete▾
✓ Compatible — particularly effective on pebblecrete
Copper-based algaecides are especially effective against black spot algae, which is most common in pebblecrete and concrete pools. Use at the higher end of the dosage range for black spot prevention.
💊 Dosage guide▾

All doses are per 50,000L of pool water. Always super-chlorinate first and allow 2 hours before adding Knock-Out.

🟡 Mildly green pool
200 ml
per 50,000 L
Slight green tinge, still partially visible. Shock with chlorine first.
🟢 Clearly green pool
400 ml
per 50,000 L
Green water, bottom not clearly visible. Full treatment dose. Run filter continuously for 48 hours.
⬛ Dark green / black pool
600 ml
per 50,000 L
Heavy infestation. May require second application at 48 hours. Backwash filter before repeating.
🔄 Follow-up after treatment
After Knock-Out clears algae, dead particles remain suspended. Add clarifier 24 hours later to restore sparkle.
❓ FAQ▾
When should I use Knock-Out vs Pool Algaecide?▾
Use Lo-Chlor Pool Algaecide for routine prevention — monthly dosing keeps algae from establishing. Use Algae Knock-Out when you've already got a green pool emergency. After Knock-Out rescues the pool, switch back to Pool Algaecide for ongoing prevention.
My pool is still green after one dose. What next?▾
Allow 48 hours and run the filter continuously. If still green, backwash the filter — a clogged filter can't clear dead algae — then apply a second dose. Also check phosphate levels with the Starver Test Kit — high phosphates allow algae to regrow faster than treatment can keep up.
Will Knock-Out work in a heavily cloudy pool?▾
Yes — but super-chlorinating first is important. Organic matter in very dirty water consumes chlorine rapidly. Shocking first clears the organic load so Knock-Out can target the algae directly.
Do I need to do anything after the algae is killed?▾
Yes — dead algae turns the water grey-green and remains suspended in the water column. Dose Lo-Chlor Miraclear Liquid Clarifier 24 hours after the algae is dead to coagulate the particles and clear the water. Run the filter continuously and backwash once the water starts to clear.