Thank you all I am going insane. I do not dose vodka. Should I what does it do? I have heard of it but that it was old school. I have two reactors. One with GFO and one with carbon. Refugium is going great all parameters show zero that might be feeding the algae? Algae shrinks at night with lights off but comes back during the day. I did a 3 day lights off and it was gone in display and then lights on it comes back. Problem is I have Xenia now and maxima clam. They require light so I can't turn them off again. I have been doing FOWLR for 12 years and I started this 90 gal reef thinking I could do everything right and avoid algae but here we are mostly due to the vacation disaster.