The Diatoms seem to be getting worse and I think it's from silicates in my water but I'm not sure, this tank has always had a small diatom problem that seems to lighten if plants are growing fast. So I am continuing to dose the PPS Pro amounts but on an EI schedule and I can't dose EI amounts because I'm holding off on any water changes thinking this is my problem. Someone else posted that diatoms are from silicates period and the water changes are the culprit, but like all algea I think we have the spores floating waiting for good conditions for them to bloom. I have read poor lighting, poor circulation, and water changes that spike the CO2 in a low tech tank can cause problems by the plants having to readjust from high to low CO2 levels and WC's should be every other month to quarterly on a low tech tank. I also noticed that the problem occured after all of the nitrates were used up from the new plants starting to take off (and a carbon pad I added for a week while one filter was down), so I have stepped up my dosing schedule a little to have a small reserve of nitrates in the water and it seem the diatom are getting worse, but I have read everywhere that this can not be the problem so I guess I'll continue at this rate for now. Thanks for your help and I'm sorry I so dang impatient.