I'm going to redo my shrimp tanks to try to more closely hit the target parameters for OEBTs. I've seen first hand how well Akadama will buffer the water to a pH in the mid-6's, but I'm looking for something different. I have a couple of "givens":
1) I'd like to make my own water using distilled from WMT and Mosura Mineral Plus Ultra.
2) I do not want to use any tap water because our well is just too unpredictable from a chemistry perspective
3) I'd like to use an inert substrate (likely Tahitian Moon Sand)
4) This will be a shrimp and moss only tank.
5) I'm looking for water with these parameters:
I know that for my existing tanks I need to add 10-12 drops of the Mosura to a gallon of distilled water to get a TDS of 120ppm or so. However, I've always used that with the active substrate and that kind of locked the pH in. But, since I don't know of a substrate that will buffer distilled water to 7.0-7.2pH, I need to get it in that range myself. Since the Mosura doesn't add kH, I'm not sure I can even get a valid pH reading. I'm considering adding a bit of baking soda to get the kH to the 2-3 range, which I think in theory will get me a reasonably stable ph. So, between distilled H2O, Mosura Ultra, and baking soda, I'm thinking I can repeatedly make water to the specs above.
Does this sound reasonable? Would that allow me a stable pH value? Should the fact that there is living moss cause a pH swing from day to night? I know that with FSS or Akadama the moss grows just fine with no additional chemicals of any kind. Do you think the shrimp poo is enough to keep the moss alive with an inert substrate?