andywg
Bored into leaving
The pH scale runs from 1 to 14, so I would hardly describe 6 as at the top end.Good point - but fish that prefer more acidic water, like angelfish, neons and rams, still only live in around 6.0/6.5ph waters - which is still at the top end of the scale.
For lowering pH you can use RO water mixed with tap, or collect rainwater.