I’m currently experiencing a Diatom bloom (confirmed microscopically) in a tank that should not be having one (older, established) and I’m trying to chase down the Si source. RODI is coming out 0 tds and color changing resin is still good. The only thing I’ve been dosing more of recently has been the AB+. I’m going to stop it for a while to see if the population crashes but wondered if anyone else has had this happen.