Okay, I'm going off well water, so yeah, there's no one who... regulates it, I suppose you could say. But I will get a test kit for the KH/GH as soon as I can and get back to you. The fish I'm mainly working with here are blue rams, cockatoo cichlids, and severums. The rest of my tank parameters are fine, 0 ammonia, 0 nitrite, less than 5 nitrate, and yet the only time I've been able to keep the blue rams alive was when the pH was at 6.5.
One other option for testing GH and KH is at a reliable fish store. Some will do such tests. I only suggest this because once you test the water and know the GH/KH, you may never need to test again. But if the few dollars for the API test (which is GH and KH) is not an issue, go for it. Make sure you get the liquid test, not strips.
To your fish. Aside from my comments momentarily about the source of the apisto and ram, these species mentioned should not have issues in the pH of 6.8 to 7.2 range. We still don't know the GH, and with a well this could be an issue. I will reference both GH and pH ranges in my subsequent comments.
The severum is probably the species
Heros efasciatus which is the species usually seen as "severum;" the true species,
Heros severum, is apparently almost unknown in the hobby, unless you are a cichlid specialist. Store-bought fish will almost certainly be
H. fasciatus. And likely tank-raised fish. The GH range is soft to moderately hard (about 4 to 15 dGH), and the pH range is 6.0 to 7.5 roughly speaking.
The cockatoo,
Apistogramma cacatuoides, is an exception among the South American dwarf cichlids in having a wider range in GH and pH than most. Here again you will likely encounter tank-raised (commercial) fish, and their tolerance is roughly < 10 dGH, and up to 7.6 in pH. Wild caught fish are very different, requiring very soft and acidic water. If you acquired this species from a direct importer from South America, they will be wild caught. But most store fish will not, as this species is now widely raised.
The common or blue ram is similar. Store fish will almost certainly be commercially-raised fish, unless the dealer imports directly. This species,
Mikrogeophagus ramirezi, should be maintained in water parameters similar to those in which it was hatched and raised. Unless you can ascertain the exact hatchery, or you know the hobbyist breeding them, this is probably going to be difficult to determine; we are not talking the supplier, but the actual hatchery. But given the situation in North America, if that is where you live, I would suggest that you should have no issues in your water (subject to the GH determination).
You previously mentioned no luck with these fish in your water, so once again the GH may be the factor we are dealing with. Or perhaps being well water there are other issues: minerals like iron, calcium; nitrates especially if in an agricultural area. Have you tested your source water for nitrate (and ammonia and nitrite while you're at it)? Any of these can be present. And while some will say nitrates are not that important, we now know differently. Cichlids are in fact highly sensitive to nitrate, long-term. I can go more into this if we have a nitrate (or amonia/nitrite) issue.
Byron.
