Just been reading this post about diatoms algea,iv had a tank running for 2 years now so it is very mature,over the last 7 months I have had diatoms in my tank I have tryed everything to get ride of the this algea and nothing has keep it at bay,iv tryed blackouts,dosing hydrogen oxide,algeafix,raising the co2 really really high,my guess to 50 or 60ppm as I run a wet and dry sump filter with high O2 in my tank, lowering light,running high light,nothing has worked,every time I dose ferts I see a bigger outbreak of diatoms,at the moments I am just trying different things to try to combat this algea I have not dosed the tank for 2 weeks now and I am seeing a bit of a inprovment as I am not getting diatoms over the new grow that is coming though,where as when I was dosing I was getting the whole plant covered in the stuff,I have tryed to vacoom the substrate this morning to see if it is something leaching out of the substate that is keeping the diatoms from going,hopefully I will do this over the next few weeks and see better results with the diatoms,iv been in to the planted tanks hobbie for the last 10 years now,and all I read on forums is to raise the co2 to fix every algea outbrake in anyone's tank,I think this is the wrong advice for people,it makes people think thay need crazy amounts of co2 in there tanks to have a stunning tank and this is completely wrong,your gonna have this magical tank if you find a way to disoIve crazy amounts of co2 though your reactors and in to your tanks. I have seen stunning tanks and had very nice tanks myself that were run on very low c02,low flow,low light,the opposite to all the advice you get on forums,I just think high co2 to fix everything is not the case,well I no it isn't.