Hi all. I have a yellowish to reddish algae growing in my sump. It seemed to start after dosing phyto in the sump. It's only growing on the silicone (I assembled my own sump baffles). Used GE silicone. Water parameters are spot on with phosphate a little higher at 0.1ppm. Tank in it's existing format is 6 months old but I began cycling rock etc a few months prior. This algae will not run off easily like diatoms or cyano. It ia not present in the display tank. I have no significant other algae issues in the sump or display tank. The sump is in the basement where I start garden seeds, there are grow lights but not directly on the sump.