Thanks for the reply.
There isnt any CO2 being injected into the tanks. Other parameters are
Ammonia: 0
Nitrite: 0
Nitrate: 0
Chlorine: 0 ( as tested by tetra test strips)
Water comes in from the tap from the city. There is no degassing tower or tank. I don't notice any redness or burst capillaries, however from time to time I do notice some drooping tails.
I am not sure what a TGP meter is.
Yes, the tanks are freshwater. I agree that the ph at 8.2 isn't necessarily a problem but a symptom of a bigger issue. As far as aeration, we do not do anything special there, tap water chlorine is removed via degassing in the sump prior to being pumped up into the tanks. We change the carbon filters once monthly and the UV lamps get changed 2 times a year, every 6 months. Specifically, the tanks are Marineland commercial systems. We do a constant temp of 76 across the board. I find that hardier fish are able to survive, however most tetras, mollies, etc. are not doing as well. I have variatus and zebra danios that have currently been living in there for about a month. African cichlids are also loving it