I'll apologize from the start that my post is going to jump all over and ramble a bit!!
I've kept (usually successfully!) aquariums for a good 25ish years now. I've always subscribed to the theory of letting aquarium fish adapt to the water out of the tap
wherever I've lived in order to keep it simple. I've bread numerous fish and generally had very healthy tanks. I'm in the military and have moved a lot, hands down, the vast majority of places that I've lived have had very hard water in the 8.2+ range. I usually haven't had any trouble with most of the common fish we all see in big box stores, etc. (in other words, most livebearers, African Cichlids, even tetras/barbs). I've always been fanatical about regular maintenance, water changes, etc. and I know that stabilization is usually the bigger factor as opposed to a spot-on particular hardness or pH.
There have been fish that I've wanted to keep over the years (Discus, to name one) that have reputations as being difficult and/or not for beginners. In particular, I'm in love with the annual species of Killifish and am just itching to get involved in some of the various aquarium club breeder programs that are out there.
So, all of that was a build-up to my question! How does one go about achieving softer/more acidic water that is STABLE? Emphasis on the stable part! haha
I've been planning out my big dream fishroom (I'm getting close to military retirement now) and I want to focus on breeding and caring for some of the more specialized species of fish.
What I can't wrap my head around is the stability of RO water. As I understand it, after reading MANY articles here and in other places, is that running my water through an RO system lowers/removes the TDS and impurities in the water, effectively making it pure, but not necessarily lowering the pH. By making the water pure and removing buffers, isn't it much more prone to pH swings? I'm trying to learn/understand the steps to produce soft and pure water for fish that is ideal for breeding but also as stable as possible. Preferably without adding constant chemicals (aside from maybe extracts or essential minerals) or opening myself up to a disastrous water chemical situation. I've read about adding peat, almond leaves, etc., to affect water quality but this all sounds like black magic where the results may vary and fluctuate. In my mind that fluctuation sounds like a recipe for disaster. So, what do all the water guru's out there do?
Thanks in advance for any info or thoughts you might have.