What is the cause of brown algae?

[Owlbehere]

I know leaving the light on too long can cause algae to grow but what else... I have brown stuff on everything in my tank and in random spots on the glass. My plastic plants are covered in brown. Its in my older 46 and 20. Anything else I can do to help with it? My platy likes to poke at it but she gets full lol.

[Lady Hobbs]

Are you using sand? You can get a lot of diatoms from sand for several weeks but it's common in all newly set up tanks. Phosphate/silcate sponge will help in your filter as well as limited feeding but it's a common nuisance and something to tolerate for a couple months and then seems to go away almost on it's own.

You can clean your plastics in bleach water then allow to dry out well.

[Owlbehere]

Well the 46 is sand, the 20 is gravel. These are both fairly new, all cycled with previous media. I did think I saw somewhere that it does goes away eventually. I've been trying not to feed too much to keep it down. I may clean the plants next water change. Thanks hobbs

[190MPH]

I had the same thing going on in my 72g. I read everywhere about oto's eating algae, so i went out and got 2. All I can say is WOW! Those guys did a number on the stuff thumbs2: . They have been hard at work. The plastic plants, rock cave, and even the Mopani wood I have look almost like the day I put them in. I keep the front glass clean and they do the rest. I'm kinda hoping that it keeps showing up for them, they seem very happy and their bellies are fat. I do feed algae wafers once in a while though.

[Owlbehere]

I was thinking of getting some for the 46 I don't think my cory would mind. If the problem shows up in the new 46 though I can't do that because George would have a field day eating them. My 20 isn't that bad actually I just looked and the plants are clean, its just the glass and rocks... But it gets clean when I vacuum the gravel anyway. I have to vacuum the gravel well because that tank has an UGF.

[Dave66]

I quote myself:
DIATOMS

Diatoms are usually the first algae to appear in a new freshwater or marine tank, and can cover literally everything that doesn't move. It's easily removed from the glass with a plastic scraper. Other surfaces can be more challenging to remove the offending diatoms.

It shows up in new tanks usually within a month of setting them up. All it needs to get going is silicates in your water, a neutral or slightly alkaline pH, and the light that came with the tank.

Thing is, over the next few weeks Diatoms go away by themselves. It uses up the silicates, without that to keep it going, Diatoms just fade away.
Diatoms are only unsightly, not dangerous. Otocinclus will eat it. In marine tanks Diatoms are the first algae, followed by green algae and with live rock, coralline algae. Like freshwater, Diatoms fade away after a while so patience is the only weapon against it.
–––

From my algae primer stickied in the algae forum.

Dave

[Taurus]

If it is diatoms, they're very soft and easy to remove with an algae scraper. Because they are soft, that's why the otos love'em so much.

[Owlbehere]

Thanks dave, I knew I had read that somewhere, I'll just play out the waiting game :). Thats probably also why they are going away in the 20g.

[katrinka772]

My son noticed these brown spots on his silk plants and his bubble stone. We just went thru a cycle of treating for Ich and then the brown spots appeared, although his tank is still fairly new (set-up the first of April) and cycled.

His comment to me was that he needs to get the cory cats that he wants (I know panda is one of his preferred). I read that the Otos will tend to this stuff but will corys touch it?

We are new to the fish tank hobby and he is using his learning as one of his 4H projects.

[PostalPenguin]

I never saw my corys eat the stuff. Otos will devour it. The oto in my 20g looks like he is about to burst since he has so much to eat.

[bushwhacker]

when i first got my baby BN plecos i had a bad case of diatoms, i put em in that after noon and by morning there wasnt a trace of it left