Diatom Algae

[Cichlid_Man]

Hi all.
I have what they call diatom algae. Black moldy growths on the glass.
Any idea what this is from and how to control it?

Fish are all healthy and just had fry. Everything is perfect water wise.

[gm72]

Can you flesh out the rest of your setup? Planted or not? Water change schedule?

[Lady Hobbs]

I agree with gm about knowing if there are plants or not because it can mean two different things.

But I also started with the black algae and got a phosphate absorber which lowered the phosphates from 2 to .50 in my tank. However, if you have plants in your tank, you want higher phosphates so knowing which you have would help with your answers.

[Cichlid_Man]

Hi,
I do not have plants, and I do not do water changes any longer.

I replace evaporated water, that's it. About 10 gallons a week.

As soon as I stopped the water changes my fish had fry.

All my water perameters are perfect, always.

[gm72]

Without plants and without water changes? Impossible to have perfect water conditions. Without something to absorb the nitrAtes, that is.

[cocoa_pleco]

brown algae is a sign of too little light too