Thanks Diana. In my reading I have been finding what you said - that fish are not as concerned about the PH as many people think. Many fish seem tolerate to a wide range of PH as long as they are adjusted to it. What people seem to do is get a fish that prefers a high PH fish and a fish that prefers a low PH without knowing it and have trouble keeping them together. What wasn't clear from my reading was how much KH I needed to prevent the dreaded PH crashes I read about. If you think I can safely keep it as low as 3 that would make it easier - I have been shooting for 8-10KH as a safe number from what I had been reading.
I have yoyo loaches, neon tetras, and mollies. The mollies may end up at a friends tank soon as I was unaware of their brackish preference/preference for harder water - and I plan to keep softer water more in line with my tap water. The neon's like very soft water, and the yoyo's will tolerate up to a medium but prefer a bit softer as well. So in terms of a target, I am shooting for soft water that I can easily dose my tap water into when I do a water change. I don't mind adding a chemical to raise the dh/kh when I do a water change, what I don't like is the idea of every water change cause these sort of ups/down while I restabalize it if I plan to water change weekly - that seems unfair to the fish. The better solution seems to be to setup a tank with water conditions close to my tap water (or that I can RELIABLY set it to) and find fish that like that.
From what I understand, using RO water is to remove GH/KH so as not to make changing the PH difficult from the buffering. Given my water is practically nonexistent in that regard, I don't see RO being a large benefit for me?
Sorry, it was a bit of a wall of text
Tap water numbers:
Lighting is DIY 4x 13w 6700k CFL w/ metal reflector (https://www.plantedtank.net/forums/sh...d.php?t=203066
). I am adding excel daily as my CO2 source while I decided if I want to go pressurized CO2. That is why I am doing a tad less then the generic EI dose as my 65 tank falls in the low end of the 60-80 tank range and my CO2 is not a pressurized system.
I hope this makes sense. I was just trying to avoid adding my low ph/low hardness water which brings down the tank, then i dose chemicals to raise the hardness which seems to raise the ph more then I want, and then after a few days it settles back down to about 7.2 where my PH seems to hang out normally. Because my water water is so soft I will target soft water and reduce the amount of fighting I have to do with my water
What I wanted was to understand KH better - and how much I needed to prevent the dreaded PH swings - and a better way to add it to the tank. Using Seachem Carbonite seems to raise my PH temporarily as well - but that may be because I was targeting too high of a KH (8-10) before. I will have to slowly adjust my tank down and see how it goes.