FishMan wrote in :

to prevent ph crashes, and sure enough I had a low ph problem which
actually caused an ammonia problem. I have been adding ph Stable to

How do you figure the low pH caused the ammonia problem? Chances are your
tank was just going through its cycle and your ammonia problem was caused
by excessive waste and an insufficiently developed nitrobacteria culture.
Most new tanks go through this cycle within the first two weeks of
introducing fish. I have seen a low pH caused by excessive nitrogenous
wastes (too much O2 being removed from the system, etc.) but never the
other way around.

How hard is your tap water source? Unless you have something like copper
or phosphate in your water source, chances are you can just mix small
amounts of tap water with your RO water to achieve a good GH, KH and pH
balance. I suggest you aim for 1 - 2 degrees KH if you want to maintain
slightly acidic water.