Algae

Originally posted by TCLynx on AGC, June 8, 2010

Something that most people with fish tanks exposed to bright light are going to have to deal with is algae. Now if you are talking about a display aquarium or an ornamental fish pond, you may need to resort to chemical or UV means of killing algae along with cleaning it out of the system, however, in an aquaponics system we have to avoid chemical methods and we really don’t require the high tech of UV sterilization just to get rid of algae.

There is a really simple method of controlling algae in an aquaponics system, shade any open water from the sun.

Additional benefits of a cover over the fish tank can include keeping leaves and other debris out of the fish tank and depending on cover design, it can also keep fish in the tank if they try to jump out and keep children and pets out of the tank.

Here is an interesting article I once read on algae in ornamental ponds.
http://koiclubsandiego.org/library/green_water.php

Update,
For any of you who think getting the cover over the fish tank is not urgent, think again. Water left uncovered can start growing algae pretty much over night. I noticed this morning that the bins I had been washing gravel in (with system water) yesterday were already turning green this morning. If conditions happen to be right for it, algae can bloom fast and if it happens to be in a system with fish and minimal access to huge amounts of aeration, it could mean fish gasping for air before dawn. So don’t wait for the fish tank to start turning green to think about a cover for that tank cause if it starts turning green in the morning, you might not have till the weekend or even the next day to fix it (depending on the fish load and available aeration of course.)
Just your friendly service reminder.