Post #654778 by swizzle on Sun, Oct 7, 2012 7:59 PM

As someone who spent several years working in the aquarium industry let me explain what causes algae and what you can do to prevent it.

Algae is something that cannot be avoided in an aquarium or pond and does no harm other than look unsightly. Algae is a plant, albeit a very simple primitive one, that needs the same things to grow as other plants, and that is food and light. When keeping an aquarium or pond, YOU are the one who is in control of both those factors. Generally both of those things will be present but it's not until you have an excess of one, or both, that the algae becomes a problem.

Food is any decomposing matter, whether it comes from organic materials rotting in the water i.e, dead plants, driftwood, or from fish waste and excess fish food (if keeping them).

Light i don't think i need to explain, however it is always best to avoid natural sunlight hitting the tank/pond as that is something you cannot control.

Algae is one of those things where prevention is better than cure, as once it has established itself it is very hard to get rid of. If you are having a problem you need to look at which one of the two things i mentioned, food and light, are in excess and address that issue. Sometimes it is both.

A saying i always used in the pet store was that 'You are a water keeper, not a fish keeper. If the water chemistry is good the fish look after themselves'.

Same goes with algae. An aquarium/pond is a mini eco-system that you are in control of.