The Effect of Algaecide

Copper

• According to Algone, copper is the algaecide that has been around the longest. It works by stopping the algae's photosynthesis. However, plants, snails and other marine creatures can get sick in the presence of copper, because it is toxic. It also builds up with repeated use because it won't filter out and it doesn't evaporate. In March 2011, the European Union called for a ban on the use of copper sulfate as an algaecide because of its toxic side effects.

Simazine

• As of June 2011, simazine is the most widely used ingredient in algaecides. Like copper, it attacks the photosynthesis process. Unlike copper, however, it invades the actual plant and eliminates the food. The good news is that it will get rid of the algae. Unfortunately, any other plants in the aquarium will suffer the same fate as the algae.

Ammonium Salts

• Algaecides made of liquid ammonium salts do not attack the photosynthesis process. Instead, they cake onto the algae and reduce the level of water tension around it. This sudden drop in pressure causes the individual algae cells to burst from within because the internal pressure ruptures the cell walls. Called "quats" or "polyquats," depending on the chemical concentration, these algaecides will make your aquarium water look like you poured liquid soap into it if you add too much.

Alternatives

• If you don't want to add poisonous chemicals to your aquarium water, there are other methods to get algae out of your aquarium. You can scrub it off with a wire brush and remove loose parts by hand when cleaning the aquarium. You can also add a grass carp or Siamese algae eater to your aquarium, depending on your tank size.