I have some clusters around my tank where there is this black film that is growing. It is only on the sand. I run my lights for only 8 hrs a day. Checked water and everything is WNL. I have pulled some of it out by hand to get rid of it, but it keeps popping back up in 1-2 days. I have also tried to mix it up in the sand to see if that would cause it to separate. No luck still there! Any ideas/advice/know what it is.


Thx,
Steven

What else do you have in the tank and how long has it been running? Are you using RODI water to mix your salt?

I have some clusters around my tank where there is this black film that is growing. It is only on the sand. I run my lights for only 8 hrs a day. Checked water and everything is WNL. I have pulled some of it out by hand to get rid of it, but it keeps popping back up in 1-2 days. I have also tried to mix it up in the sand to see if that would cause it to separate. No luck still there! Any ideas/advice/know what it is.


Thx,
Steven
Could be cyano bacteria. There are red versions and black versions. The black is toxic and I would not stir it up. Any pics

Tank has been running for a several of months now. I use RO water to do water changes and top offs. I have 5 fish: clown, pearly jaw, lawnmower blenny, six line, and blue damsel; 1 cleaner shrimp; 1 sand sifting star; rose bubble tip anemone(doing very well), 4 types of zoas, 2 shrooms, random clove polyp, and kenya tree. In the fuge have chaeto, mud, copepods; filtering media(charcoal, purigen, phosgaurd, sponge) and skimmer.

no pics . . . new to the forum, how do I post pics?

tried to and pics . . . seeing if drag and copy works??!!file:///C:/Users/User/Desktop/DSCN1199.JPG

I'm with john... Its black cyano. Do a search of how to rif of it... I had cyano once and just left the lights off and wrapped paper around the tank for 4 days and it went away

Okay, best advice i found online was to turn off lights(but it is still okay to run actinics) for 3-4 days and possible increase of flow. So that's what I am doing right now until some tells me that I should do something else . . .

I picked out the majority of it by hand as well to help the process along

Steven

Best to syphon it out with a hose..instead of trying to hand picking it out..

Check out wet web media. I would take your corals and fish out to quarantine.