Control Red Algae

Red algae are common in marine and saltwater environments but much less likely to occur in freshwater environments. Freshwater red algae species are most often found in low light and nutrient-poor running waters. The following options can be considered for how to control red algae.

Click here to read more about identifying these algae.

 

Manual/Mechanical Control:

If you are considering how to remove red algae, physically changing the pond water can be an effective method of control. However, this is not a realistic solution for most situations. Algae can re-grow from any spores or fragments remaining in the water, as well as weather conditions such as warm temperatures.

 

Algaecide Control:

There are multiple options for how to kill red algae that offer great control. Copper algaecides generally offer the best algae control. Copper algaecides are not recommended in ponds with trout, koi, or channel catfish. Sodium percarbonate algaecides are a good alternative.

 

Copper algaecides:

1. Mizzen (for ponds or lakes) – liquid that is diluted with water and sprayed over the algae, fast-acting. Re-apply when algae bloom again.
2. Copper sulfate (for lakes) – granules that are broadcast over the algae, fast-acting. Re-apply when algae bloom again.

 

Sodium percarbonate algaecides:

1. Cape Furl (for ponds or lakes) – fine granules (almost a powder) that are broadcast over the algae, fast-acting. Re-apply when algae bloom again.
2. GreenClean (for ponds or lakes) – fine granules that are broadcast over the algae, fast-acting. Re-apply when algae bloom again.

 

Prevent Algae Growth:

There are no products available that can completely prevent algae growth. Directly managing nuisance algae growth through regular pond algae treatment or removal efforts will always be important for pond algae control.

However, you can work to limit algae growth by reducing the nutrients that algae need to grow. Reduce nitrates and nitrates through the use of SparKlear. Add PhosControl to reduce phosphorus levels. Phosphorus is the main nutrient for algae growth, and removing the phosphorus from the water is a proactive effort for algae reduction.

 

• PhosControl (for ponds or lakes) – fine granules that are broadcast into the treatment area. Bonds with the free phosphorus and some other organic materials. Use when there is minimal plant and algae growth (spring and fall).

• SparKlear (for ponds or lakes) – pellets that are broadcast or liquid that is diluted and sprayed into the treatment area. The beneficial bacteria dissolve the excess nutrients. Continue adding SparKlear throughout the season for maximum benefits.

 

Treatment Tips:

When treating red algae,

• If the algae are around the perimeter, treat the whole perimeter.
• Treat no more than half the pond at a time, about two weeks apart.

 

Additional Algae Resources:

Toxic Algae: What They Are and How to Prevent Them

Is Pond Algaecide Safe for Fish