Im running phosguard GFO from seachem 24/7. And a lot of it in a reactor. Also running GAC in a reactor. There is no dino in my sump that I can see. Its deffo photosynthetic, when lights go out, it retracts completely. Dosing voldka, I should have a heavy skim right? Well Im not getting much at all, Watery clear/white foam. I know my skimmer is working normally though. I cleaned it last night as running all this GAC has made it black inside on the neck. Im going to dose voldka for 3 more days. If nothing changes or it just gets worse, then I will stop dosing. Only thing I can think of that I did right before all this started, was dosing baking soda and kalk manually. I probably OD it a bit in the beginning. Thats when this stuff started showing up. I bypassed the kalk reactor yesterday and just running RODI ATO. Ph, seems fine now with the skimmer venturi ported to the window and my CA is higher than my test will even go so no need to dose any more kalk for now. Ive only got 3 peices of SPS and a clam that need a lot of CA.