Algae Control

Manage algae in ponds and water features with the treatments and equipment in our Algae Control collection. It includes Arbourdale Blast and Algae Armour pond treatments, Aquascape Barley Straw Extract in standard and Professional Grade sizes, Aquascape Concentrated Barley Straw Pellets, and the Aquascape IonGen System G2 electronic water clarifier.

These products are for backyard pond owners and water gardeners who want a cleaner-looking pond through the season. The right product and amount depend on your pond, so call or text 1-855-752-5795 for sizing help from our team.

Start by identifying what you actually have

• Green, cloudy water — suspended single-cell algae. Responds to UV clarifiers and beneficial bacteria; a liquid algaecide clears it fast but it will return without nutrient control.
• Stringy mats floating on the surface — filamentous algae, often called blanket weed or string algae. This is what most contact algaecides are formulated for. Rake out the bulk first so you are not treating dead mass.
• Slick coating on rocks and liner — normal and largely harmless. Treating it is usually unnecessary.
• Rooted plants with visible leaves and stems — not algae at all. That is aquatic weed, and it needs a weed rake or aquatic weed cutter, not an algaecide.

How to treat without killing your fish

The most common mistake in pond algae treatment is dosing the whole pond at once. Decaying algae consumes oxygen as it breaks down, and a large kill-off in warm water can drop dissolved oxygen far enough to suffocate fish. Treat no more than one third to one half of the pond at a time, wait 10 to 14 days between treatments, and run aeration throughout. Always dose to measured pond volume rather than estimating.

Aeration is what makes treatment safe and what makes it last. Pond aerators and aeration systems keep oxygen up during die-off and let beneficial bacteria digest the organic sludge that feeds the next bloom.

Keeping it from coming back

• Beneficial bacteria — consumes the bottom muck algae feeds on. The single best long-term investment.
• Pond dye — blue or black dye limits the sunlight reaching submerged growth. Cheap, safe and effective.
• Phosphate binders and clarifiers — strip out the phosphorus driving the bloom.

Common questions

Is copper sulphate legal for pond use in Canada?

Aquatic herbicides and algaecides in Canada must be registered with the PMRA, and what is permitted varies by province and by whether the water body is private or connected to a natural system. Always confirm the product is PMRA-registered for your intended use before applying. Our guide on pond algaecide covers what is legal and what actually works.

How long does algaecide take to work?

Contact algaecides typically show visible results within 24 to 48 hours on filamentous algae. Water clarity from suspended algae can take longer. Rake out dead material rather than leaving it to decompose in the pond.

Why does my algae keep returning?

Because algaecide treats the symptom. If nutrient load, sunlight and stagnation are unchanged, regrowth is guaranteed. Add aeration, bacteria and dye and the problem shifts from recurring to managed.