Hello I have a 13.5 evo and it’s been up and running for 4 months now.This is my first ever saltwater tank and I’ve been learning a lot as I go along, however I’ve been having some issues recently and i definitely need help, Issue number 1 hair algae problem for about a month now and I have just recently lowered my lights down to 6 hours with a 1 hour and 30 minute ramp up/down time also have added chemi pure that removes phosphates which mine were high so I think I have that under control, my next problem is I believe my oxygen level might be low and I do not know how to fix this issue my snails and starfish are going to the surface at times also at times I notice my fish breathing rapidly, I feed one full block of frozen mysis per day, I am running a AI prime, auto top off, stock pump, stock heater, chamber one in tank with a filter sponge on top to catch the loose hair algae and right believe that is the chemi pure. I have 5 different Zoas, a Duncan, two recordea mushrooms and two separate colonies of GSP, also have sand sifting starfish, Halloween crab, urchin, and two snails. Also any advice on what to do next like anymore upgrades or anything like that I will try to figure out how to upload a picture. Thanks !