One of my tanks is covered in brown algae. I have no idea what is causing it but it is on everything and I can't get rid of it...

Is it your new tank that you just set up and cycling?

No this is on my 75 bow front that has been set upfor months, and the filters were already cycled.

I would do a good cleaning with an algae scaper and then do more frequent water changes.. also I would cut down on the light to the tank as well.. algae needs light and the waste from left over food and waste from the fish to grow.. doing a good cleaning with more frequent water changes and less light should cut down on your problem...

If there is anything else Nick feel free to ask

i was told by a friend that at 0 nitrate reading, a brown algae is a diatoms. They favor a low light environment...but rely on nitrogenous waste, either nitrites or nitrates. if your reading 0 on both. if you are leaving the lights on longer, it encourage green algae growth... It's hard for green algae to overcome brown algae/diatoms at deeper depths...where light penetration is minimal...but if not getting any green algae at the shallower depths,and having 0 nitrite/nitrates, it's possible that you have a cyano-bacteria growing instead of a brown algae/diatom.

Nothing but a canister has changed in this tank, I set up the canister that I got with the tank. Does it make any difference if this filter was run on a saltwater tank before? The tank itself is clean. I make sure I keep it that way as you never know when these Jags will lay eggs again. And you do not put yoour hand in there when there are eggs. LOL

So I am at a loss. The light was off for 3 days last weekend and thats when this showed up. They were also not fed durring this time.

Nickisue wrote:

thats it.... low light or the absence of light. when you put on the
light, green algae will overcome the brown algae but i know you don't like the green algae either

I am about ready to drop about 5 plecos in there for the day and let them handle it. How do I make it go away? The light schedule has been back to normal for a week.

just scrape the glass wall with scoring pad and let the filtering
system cover it for you. with enough lighting, they will eventually
succumb to green algae and your water will be cleared.

Thanks Paul.

Thanks from me too, I'm having the same problem in the big tank but it's on the rocks which are harder to clean.

i have brown algae on my rocks and my pleco will not touch that stuff he likes green algae and wafers and left over krill / shrimp. He refuses to eat the brown stuff!