I also have some different opinions about algae. The word "algae" strikes fear in many novice aquarists hearts, and volumes have been written on how to cure a tank of nuisance algae. I submit that algae cannot be cured because it is not a disease. I almost always have some type of algae growing, and I only fear it if it dies. Algae grow on every healthy reef on earth. If it did not, what would urchins, slugs, tangs, snails and various blennies eat? Those animals are there because algae is there. One typically does not see much algae on a reef because of the hordes of these animals, many of which appear only at night.
What would happen if 80, eight-inch tangs were released in your 50-gallon tank for the daylight hours, and 50 urchins feasted all night? Do you think you would see any algae? It grows in the sea on everything - as it should. To my way of thinking, a little algae is a good sign, not something to go crazy about. A very clean, sterile looking tank is not necessarily the healthiest tank. I have made an agreement with algae. It grows mainly where I want it to grow, and in return it keeps my water healthy. I consider algae to be the best water purifier there is, and it is host to multitudes of "pods," worms and an assortment of other beneficial creatures that would find life harsh on bare rock alone.
Since I don’t want the algae growing on my corals, I have built a five-foot algae trough. [Editor’s note: This is a filtration system known as an algae scrubber, with algae reducing nutrients in the tank.] It is a plastic trough that is positioned at the tank's surface along the rear. It is positioned partially under the main metal halide lighting, and it shields the tank's back glass from light, giving the tank a much more natural appearance. The trough provides favorable algae growing conditions by having swiftly flowing water that is only a half-inch deep and located a couple of inches from bright light. I also installed a cement-encrusted plastic window screen (algae loves to attach to cement) in the trough which can be rolled up, removed and cleaned. What more could algae want? The trough is fed from the skimmer's outflow, so it uses no power and takes up no room that I would use for other things. It is also practically free to build one using a PVC fence post sliced in half.
