My 75 gallon community tank is full of fish who prefer slightly acidic water, 6.0-7.0 pH
to be exact, and 8-12 dGH.
My tap water is off the chart pH (above 8.6, probably considerably above) and 10 dGH.
For the last 4 months (exactly 4 months, actually) I have been using 2 pieces of African Mopani wood and a product called Proper pH 7.0 in this tank, and have had exactly 8 dGH the entire time, and a pH consistently between 6.6-6.8. The fish are thriving and breeding in these conditions, and that makes me happy.
However, the correct dosage of Proper pH 7.0 for this tank means I go through lots of bottles of that chemical, and it is getting really expensive. So I am thinking about other methods to acidify my extremely alkaline water to the levels that my fish prefer. And yes, I know they could probably adjust somewhat, but between spending a lot and making them adjust to conditions that aren't ideal for them, I'd rather continue spending a lot, no contest whatsoever. More over, my tap water pH is beyond reasonable levels for most fish. I know that none of the other chemicals meant to acidify water will work for me, most of them just bounce right back to extremely alkaline, and the last thing I want is to have a constantly and radically shifting pH. And my bogwood does not make enough of a difference by itself.
So I was thinking about getting some peat and using it, perhaps in the filter. But I'm not sure how to use it, how much to use it, and I am very concerned about the hardness going down to the point that my water has no buffering capacity, and my pH then going absolutely crazy. I was hoping that someone with experience using peat could help me with these issues.
I would also like to hear from people who have used other methods besides peat, bogwood, or chemicals. (If there are any other reliable ways).
Sorry the post was so long, thanks for reading it!