I've been thinking that I have dinos in my 2 and a half month old tank but now I'm thinking it's diatoms due to some research I just did. I don't see anything that looks like bubbles and although it's annoying when this stuff gets all over the rocks, it is brown and dusty (I can easily use a toothbrush to brush it off)...my nitrates are far below 5 and my phosphates measure at .25 although someone told me not to trust the salifert test. The tank has plenty of live rock from the ocean in it and only has one starfish in it right now and a lot of coralline algae which I'm trying to get to grow over all the rocks in the tank. What do I do about the diatoms? Are they harmful or hard to get rid of??