Hey john, Have you noticed at all that fish have issues at night with breathing? esp with macro algae / seagrass tanks? im guessing im seeing some die off initially when i first get fish. and it happens at night EVERYTIME. how do you avoid this esp if you dont run a skimmer at night on a heavily planted/ seagrass tank? given plants will "eat" the o2 from the water at night? and only releases oxygen during daylight?

Never noticed this. How far is your ph swinging?Would have to disagree that is the case, they don't release more carbon dioxide then they put in, and your average O2 level should be the same. Are the fish schooling at the surface at night?

some yes. but it seems that the die off has ended... strange. all from the same guy. but i did email him and let him know about it. he mentioned his system for his fish maybe TOO different from my tank. but his inverts system is similar to mine? not sure how he knows this but im sure he is doing something like hypo for his fish and when they came to my system it was a shock. (this was a guess by the online florida retailer)

Do you place shipped fish directly in your tank? They need to be by themselves in isolation for 1 week or more to survive. Otherwise they die usually after 4 days in the display. I am not sure why this happens, shipping stress, fish pick on the weak etc... Not sure, but I have noticed this.