Brown Algae,water change, and lighting questions........?

Question

I have had a 5 gallon tank with 4 female Bettas for about 4 months now. I've done about 95% water changes every and replace my whisper filter cart. about once a month. Recently I have discovered the growth of hat I think might be Brown Algae. At first I thought it might have been from a few stones I put in the tank but it spread to the fake plants and walls and seems to stay in one corner where the filter dumps water.

I also changed bulbs from stock to more expensive blue/white florescents about a month ago. Light stays on from about 7am til 11pm but my room is pitch black during the day with ZERO sunlight in a garden unit apt.

What could be the cause of this? Too many water changes? Too much water taken out during each water change? Too much light? Not enough light? Should I feed once a day instead of twice a day?

How harmful is this brown stuff. All the fish seem pretty healthy. just need advice on how to prevent or rid of the brown stuff.

Thanks in advance

Almost 100% water change once a week. As much and the thing can suck out.

Also forgot to mention the temp is a little over 80.

Answer 1

If what you're seeing is just on the gravel and plastic plants, it's probably either brown algae or diatoms. Your question didn't mention how often you change your water, but a 25% change each week is usually enough, and less stressful on your fish than larger changes.

While it's true algae needs nutrients to grow, I doubt if these are the main cause if you're doing 95% changes, unless they're very infrequent. You can cut back on the amount of time your tank lights are on though, or keep them off until the problem is under control. Algae needs light for photosynthesis, so the longer the lights are on, the better for it. You can just leave the room lights on. or any curtains or shades open so the room has indirect lighting.

If the brown is caused by diatoms, these need silica to survive. You might want to check your tapwater, or any additives you use for this. Both algae and diatoms need phosphate, which some water suppliers add to their water to reduce pipe corrosion. You can remove this with a pad you can cut to fit in your filter. Snails are also a way to remove these from the gravel.

See the links below for more info on these: http://www.skepticalaquarist.com/docs/algae/algcont.shtml
http://www.skepticalaquarist.com/docs/algae/diatoms.shtml

Answer 2

I have a 10 gallon tank, I had the same problem that you r having, the person at the pet store told me to feed my fish every 2 days don't leave the light on all the time,and get a algae eater..Have you tried a different whisper filter?