Scrape and erase.

No, it's not how I do the dishes. It's what I have to do to the fish tank. See, there's this green algae starting to grow on one wall of the tank.

In most cases, green is good. In this case, it's a living wallpaper that will take over if I let it get out of hand. A little scrubbing, a little water change, and everything will be fine.

Algae, a sort-of-but-not-really plant, is actually a necessary part of the world's oxygen supply that drives fish keepers crazy. It grows in fresh or salt water, thrives on light and fish waste, and comes in several festive colors.

If you find algae in your tank, you can be at least a little bit pleased. Algae consume what fish leave behind. Without algae, that stuff would create a toxic tank environment. At the same time, algae can go bonkers and take you with it.

To reduce the amount of algae in your tank, try some simple, natural techniques. First off, keep your tank out of direct sunlight. Light and fish poo equal algae, so cutting back to one out of two ain't bad.

Check the water conditions in your tank. Are the pH and other levels where they should be? Lopsided levels can lead to excessive algae.

If you do get a touch of the green (or red, or brown, or...), you can remove it with good ol' elbow grease and an algae scrubber. Skip the household cleansing pads, which are often loaded with harmful chemicals. Avoid cleaning more often than once a week. Too often will not only remove beneficial algae, it'll freak out your fish.

Once your tank is clean, you can admire your happy, thriving fish and curl up with a good book. How about Breakthrough by Stephen Tremp? It's his birthday, and buying a book is a the perfect present for an author.

Do you keep fish? What's your number one tank chore?