First step is to *stop* medicating and get the tank under control. We know Nitrate is high, and PH
in a healthy tank should be around 8.2 *without* having to induce it with a water change. Green/cloudy water syndrome is in my experience quite often caused by low PH
and/or using shop lights on your tank with crap water supply. Better tank health, proper PH
and breakdown of nitrates mean you have to do fewer water changes and hence dump less garbage into the tank to feed the nuisance algae, so the problem solves itself. Some people claim that doing aggresive water changes on marine tanks solves problems, but all I find is it either puts a bandaid on the real problem, or causes more issues.
I'm also noting you said LR
was in the sump, but no indication it's in the main tank. My experience with LR
is when it's placed in a sump it acts like nothing more than a big bioball with poor efficiency. I'm also curious how much circulation is going on in the main tank.
To sum this up, it looks like we have a big tank with insufficient or poorly placed LR
and questionable circulation, so it turns in to a big algae swamp with poor oxygen, high nitrates, and erratic PH
. That's why your angel is lying on it's side gasping for air because the water can't hold it. No mention of a skimmer either, which combined with some healthy live rock or sand and good circulation will put a lid on the nitrates.
My biggest suggestion is to find a pet shop shop in town with a tank about the same size, and in good health. Try to emulate what they've done to get it healthy, which usually means a hundred pounds or so of LR
, skimmer, and strategically placed power-heads in the *main* tank. Note that dumping a bunch of LR
in an established tank that size will likely cause instability for a few months as the rock cures and adjusts, and that means treating you current inhabitants as if they are going through a fresh tank cycle.