FishFolk

I have a dark brown substance - I guess it is algae - in my 55g freshwater cichlid tank.It is on the tops of rocks, a sea shell and holey rock, a little on the tank. I have taken the holey rock out, boiled and scrubbed it clean. It begins to be covered in a few days. I use the scrub brush to clean the tops of some ofthe rocks. It comes off and looks powdery - but in reality isn't, it just looks that way as it disperses.

I read that brown alagae could be diatoms. This could be but it isn't in clumps and doesn't match the pix I saw.
If it is diatoms, it could be lights:
My lights are goodness knows how old. Recently ( a week ago) did a temp swap with Cory d55 as he needed a split system to accomodate a huge plant he bought. His light is about 10 mos old - so it could be the light. I leave my lights on 12hrs and off 12hrs.
If it is diatoms, it could be filter:
Diatoms are said to be a new tank issue and mine is 4 mos old BUT I changed filters about 2 weeks back. Swapped from HOBs to a Rena XP2. I put in old ceramic rings to keep the bacteria right. And I added 3 small yellow labs but took out one m greshakei. Could the new filter be it?

Nitrates are usally 0-10 but today were up to 20 before the water change - another culprit, I suspect. Nitrates have been about 10 for the last week or so.

I was at LFS (before today's test) and asked what they suggested. They said less food, less lights.

If it is diatoms, some here say better lights and time will fix it. Some advocate an algae eating fish. I have lots of alb bn plecos and could put a couple in but have to sex out a few pair first.

Bottom Line: - Does this sound like diatoms? Do I try all the fixes? New bulbs, less food (I know less food will help nitrates) and an algae eating fish? Or do I just give the filter time to get "old"?

Butterfly

Sounds like Diatoms Is this a new tank?
Carol

FishFolk

No mine is 4 mos old BUT I changed filters about 2 weeks back. Swapped from HOBs to a Rena XP2. I put in old ceramic rings to keep the bacteria right. And I added 3 small yellow labs but took out one m greshakei. Could the new filter be it?

04_si

small changes can make the diatoms come back. i changed the light and now have an outbreak of the diatoms, so im sure changing the filter could have the same effect.

did you seed the new filter as well?

Coryd55

Coryd55 used my comp and logged on - I didn't notice it when I navigated to FL, but it came up as him- This post is actually from me - FishFolk
Yes - I seeded the filter.

I know the diatoms are supposed to go away...but grrrr. I needed to rework the rocks anyway - cichlid construction was taking its toll and I was starting to worry about the stability of the rock stacks - Soooo. Pulled it all, scrubbed the rocks and shells , wiped the walls, H2o change and back together. I have also added 2 plecos. They were definately cleaning a path, but the tank was too brown for me. We'll see what happens in a few days. Maybe with a headzstart, the plecos can handle it if it starts again.

Thanks for the info on the light -