Greg G. wrote in message
...
...

...Now, a year later, the water coming from the tap has a pH of 8.3!

But your aquarium environment has matured and, depending on your setup, if
it's planted moderately-to-heavy, may be able to handle 25%+ weekly water
changes - test aggressively until you get the hang of it.

My tap water is over eight-degrees and I do weekly 1/3 water changes into my
75-gallon with no problem (3 wpg w/ 3 DYI CO2 bottles).

...Also, water changes are causing algea blooms.

City water? Test for phosphate. Not that there's much you can do about it,
other than to crank up the lighting, CO2, and trace mineral to attempt to
compensate.

Good luck.