Very low pH levels from well water
I recently moved into a new house and of course brought my fish along with me in a new 150 gallon tank, and after I had set up the tank and checking water parameters, I realized my pH levels were really low.
First tested with my test kit, and it came out yellow. I thought the test kit was bad, so I whipped out my AquaController Jr that was still packed away, configured the probe, and dropped it into the water... and sure enough, my pH was around 5.5.
Right now, my probe is telling me the water is 5.26. I have also tested my tap water, even the RO water, all in the same 5.25-5.5 range, so it's not something going on with the tank itself, it's just my water (well).
I was wondering how this would affect growing plants, in particular with CO2 injection, and if there is anything I should watch out for.
I was considering setting up my old 75 gallon tank in the basement to store some RO water for my semi-weekly changes (the RO system was in the house when I bought it, it's pretty small... only 15 gallons/day).... but then I was considering putting crushed coral in the tank to buffer the water back to the 7 range.
If I do this, would the water unbuffer itself back to the 5.5 range when taken out of the tank w/ the crushed coral? Is there anyway to alter the pH of the water in those storage tank reliably before pumping it into my main tank?
I've read different things about whether the low pH would even affect either the fish or plants, but I'd really like to be able to work in the 6.6-7 range.