Black Spot Algae Killer 1L

Lo-Chlor Black Spot Algae Killer 1L

SKU: 50BSK1L
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$40.90
$38.24
$40.90
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Black Spot Algae Killer 1L

Lo-Chlor Black Spot Algae Killer 1L

$38.24 $40.90

Lo-Chlor Black Spot Algae Killer 1L

$38.24 $40.90
Lo-Chlor Chemicals
90% Tri-ChlorNon-metallic formula
Pebblecrete specialistDirect contact treatment
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
Black Spot Algae Killer 1L
⚫ Black spot specialist 90% Tri-Chlor formula Non-metallic Pebblecrete & plaster
📋 How it works

Lo-Chlor Black Spot Algae Killer is a concentrated 90% Tri-Chlor liquid algaecide specifically formulated for killing black spot algae in pebblecrete, white plaster and tiled pools. Unlike copper-based algaecides, it's non-metallic — which matters in pools where copper staining is a risk.

Black spot algae (cyanobacteria) forms a tough protective layer that standard algaecides struggle to penetrate. Its concentrated chlorine-based formula stays in contact with affected areas longer, breaking through the protective coating and killing algae at the root.

Lo-Chlor Black Spot Algae Killer details

  • Concentrated 90% Tri-Chlor formula — specifically for black spot algae
  • Non-metallic — safe for systems where copper-based products are unsuitable
  • Granules sink and cling to affected areas for extended contact time
  • Not affected by high chlorine levels
  • Low pH promotes better penetration and performance
  • ⚠ Only suitable for pebblecrete, white plaster and tiled pools — not fibreglass or coloured surfaces

For the granular form of black spot treatment, see Lo-Chlor Pool Blackspot Algaecide Remover (granular). After treating black spot, remove the food source with Lo-Chlor Starver X to prevent regrowth. Dose Lo-Chlor Pool Algaecide monthly as ongoing prevention once the pool is clear.

🔍 Does it suit my pool?

⚠ Important: Black Spot Algae Killer is only suitable for specific pool surface types. Check compatibility below.

🧂Salt chlorinated
✓ Compatible — works with all salt systems
Black Spot Algae Killer is compatible with salt chlorination systems. Apply directly to affected areas with the pump running. The product is not affected by elevated chlorine levels.
💧Traditional chlorine
✓ Compatible — most common use case
Black Spot Algae Killer is designed for chlorine pool environments. Apply after super-chlorinating for best results, then brush the treated area vigorously after 24 hours.
🪨Mineral / magnesium
✓ Compatible — works with mineral systems
The 90% Tri-Chlor formula is compatible with mineral pool chemistry. Apply directly to black spot affected areas. Brush before and after application.
Ionised / Nature2
✓ Compatible — preferred over copper-based in ionised pools
Unlike copper-based algaecides, Black Spot Algae Killer is non-metallic — making it the preferred black spot treatment for ionised pool systems where additional copper should be avoided.
🏊Fibreglass
✗ Not suitable for fibreglass pools
⚠ Black Spot Algae Killer should NOT be used in fibreglass pools. The Tri-Chlor formula can bleach and damage fibreglass surfaces and coloured pool coatings. For black spot in fibreglass pools, use Lo-Chlor Pool Algaecide at the higher black spot dose rate instead.
🧱Concrete / pebblecrete
✓ Primary use — specialist treatment for pebblecrete
Pebblecrete and concrete pools are the primary use case for Black Spot Algae Killer. The concentrated formula is designed to penetrate the protective coating of black spot algae on these surfaces. Apply directly to affected areas, wait 24–36 hours, then scrub with a stainless steel brush.
💊 Dosage guide

Apply directly to affected surfaces — do not dilute. Remove automatic pool cleaners before application. Adjust pH to 7.2 before treating.

⚫ Direct application
Apply to affected area
Pour or squirt directly onto black spot patches. The liquid clings to vertical and horizontal surfaces.
🔁 Wait & scrub
24–36 hours
Wait 24–36 hours then scrub vigorously with a stainless steel brush. Repeat until algae is removed.
🔄 Maintenance dose
250 ml
per 50,000 L
Monthly maintenance dose to prevent re-establishment. Combine with Lo-Chlor Pool Algaecide for full algae coverage.
🧪 Check phosphates
Test with Starver Test Kit
Black spot returns quickly when phosphates are elevated. Treat with Lo-Chlor Starver X after clearing the algae.
❓ FAQ
Why is my black spot coming back after treatment?
Black spot algae has a very tough protective casing and the roots penetrate deep into porous surfaces. Regrowth is usually caused by: (1) incomplete brushing — you must scrub vigorously with a stainless steel brush to break the protective layer; (2) elevated phosphates providing a food source for regrowth — test and treat with Lo-Chlor Starver X; or (3) insufficient repeat treatments for heavy infestations.
Do I need to lower my chlorine first?
No — unlike some algaecides, Black Spot Algae Killer is not affected by high chlorine levels. You can apply it at any point in your chemical routine. Lowering pH to 7.2 before treatment does improve penetration, so balance that first.
Can I use this on a coloured plaster pool?
Caution is advised on coloured plaster surfaces — the Tri-Chlor formula can cause localised bleaching at the point of application. Test on a small, inconspicuous area first. It is safe for standard white plaster and pebblecrete.
How is this different from the granular blackspot product?
Both are Lo-Chlor black spot treatments. The liquid (this product) is easier to apply to specific spots on walls and steps. The Lo-Chlor Pool Blackspot Algaecide Remover (granular) uses granules that sink and settle on affected areas — better for horizontal surfaces and heavily affected pool floors. Many pool owners use both.

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