Treating Algae when glass shrimp and Daphnia are present
Q. We are about to drop some of your Coptrol into our natural pond to minimise algal growth, but we have millions of glass shrimp and Daphnia. Is it safe for to use Coptrol.
ANSWER
Both Daphnia and Glass Shrimp are highly sensitive to copper, even at very low concentrations. Because Coptrol is a copper-based algaecide, it can be harmful — and in some cases, fatal — to these delicate aquatic invertebrates. For this reason, we don’t recommend using Coptrol in ponds that contain either Daphnia or Glass Shrimp.
These species play a valuable role in maintaining natural balance within a pond. Daphnia feed on microscopic algae and suspended organic particles, helping to keep water clearer, while Glass Shrimp contribute to nutrient recycling by consuming detritus and decaying material. Protecting them supports long-term pond health and reduces algae growth naturally.
If you wish to control algae without endangering these beneficial organisms, we recommend switching to the following safer, non-copper alternatives:
Barley Straw Extract
Barley Straw Extract releases natural oxidising compounds (mainly peroxides and phenolics) as it breaks down in water. These compounds subtly alter water chemistry, creating conditions that inhibit algae growth and limit its ability to reproduce. Rather than directly killing algae, this method suppresses it over time, making it especially effective as a preventative or maintenance treatment.
It is completely non-toxic to aquatic invertebrates, fish, and plants, making it ideal for ponds containing sensitive species such as Daphnia and Glass Shrimp. With consistent use, it helps maintain clear, balanced water and reduces the likelihood of future algae outbreaks.
GreenClear Pond
GreenClear Pond uses a blend of beneficial bacteria and enzymes to naturally outcompete algae. These microbes break down excess nutrients such as nitrogen and phosphorus — the same nutrients algae rely on for growth. By consuming this excess nutrient load, GreenClear Pond gradually starves algae while also improving water quality and clarity.
This biological approach is entirely safe for all aquatic life, including fish, Daphnia, and Glass Shrimp. Over time, it promotes a healthier, more stable pond ecosystem.
What to Expect
Unlike Coptrol, which acts quickly, both Barley Straw Extract and GreenClear Pond work gradually over several weeks. However, they provide long-term, sustainable control by restoring ecological balance rather than relying on harsh chemicals. For best results, use these treatments as part of a regular maintenance routine, especially during warmer months when algae growth is most active.
Good water circulation, regular removal of organic debris, and avoidance of nutrient-rich runoff will further support their effectiveness.
