I have a Penguin 150 Bio Wheel. I have recently had a huge surge in brown algae. The only thing I can think of that I have done differently is bring the water level up to the height of the filter output (so I don't have to hear the water cascading out), and this might have caused less water circulation in the tank since the water isn't splashing into the surface anymore. Any other thoughts or advice? I don't overfeed, I don't have the tank in sunlight and I only have my light timers set on for 9 hours. Water levels are all optimal. Hmmmm

I doubt raising the water level or having less water flow would cause an algae to grow. Tell me; is this algae a bit like fussy velvet, and is it impossible to remove from leaves without dammaging them, or if you don't have live plants, is it at least hard to physically remove? I have an algae problem of this sort and I'm about to remove my biggest polluter, a 14 inch arowana ( I would be more sad about losing this fish if it were not such a bully to the other fish and not so untamable). I think I introduced the algae from a coy pond on a water lilly plant. Algafix does nothing to this algae, even in higher than reccomended dosages. I've been too lazy to test the ph, amonia, nitrates, nitrites, hardness, recently, but when I tested a few monthes ago all was good. I have a 100 gallon tank with 2 monster big powerheads working the undergravel filter. I also have 2 canister filters rated at 175 and 100 gallons max capacity respectively running, I clean them regularly and do water changes periodically, but I can't guarantee untill I check the chemistry again that I haven't developed a recent excess of waste products in the water. I've never seen in all the years I've had FW aquariums an algae of this sort. It's kind of humiliating as I thought I was a really good aquarium owner.

Your post came in seconds after mine! Does it grow short like less than a centimeter long, like velvet sort of? It sounds a lot like the crap I have. I think it might be a type of "red algae". I'm going to do some research and see what I can find on getting rid of this stuff. I'd hate to have to clean the whole tank, throw away the plants, and bleach the gravel wood and rocks.

Someone told me to look at www.plantgeek.net and I think it's a varient of red algae. If you figure out how to kill it LET ME KNOW!!!! Good luck.

on the plantgeek site, mine is definitely the brown algae as shown in the two pics under the algae section (under brown). No solutions presented. It says lack of light is a possible cause, i think i will increase light and see what happens. I'll post results.

Ok i looked at two pics under red algae and the stuff on the green leaves is what i have... black spotted fuzzy stuff. It was near impossible to remove. Hmmm.... ill look into copper. I'd rather not bleach everything, as it might just come back. Im also going to look into the tap water, because i noticed this influx when i did a big water change.