Algea problem, plz identify

[DeCoY]

Can anyone tell me what kind of algea this is, and best remedies for it, it is all over one ornament, and doesnt touch the other ornament or driftwood. It killed all my grass but leaves other plants alone, i dont get it.

I know the picture quality sucks but if anyone has some advice it would b much appreciated.

amm. - 0 nitrIte. - 0 NitrAte - 10-20 - ph 7.2
17w natural daylight x2, 40 eclipse system.

 

[DeCoY]

anyone ?

 

[phanmc]

it's hard to tell with those images but I'm guessing its brown diatom algae. Usually affects new tanks and goes away by itself unless there is an excess of nutrients in the water.

What kind of grass plants are you growing? If your tank is 40g and you have a total of 34w of light, chances are the grass plants aren't receiving enough lights and are dying, allowing the algae to take over.