put some macro algae in there and watch the pH climb.
Ph is a function of kh and co2. More co2 power ph. As plant life like algae consume co2 and return oxygen during lights on, pH will rise. IMHO what is important is the tank become a net consumer of co2 and producer of o2 each 24hour period.
1) always use the high range ph kit.
2) always measure pH just before lights out.
I also recommend you use Dr Randy Holme-Farley's improved diy 2 part system. It will not only "solve" and pH "problems" but also calcium, alk, and magneuium using inexpensive ingredients.
my .02
Dr Randy. send my payment to the beaslbob benevolence fund. LOL
For others reading this--I receive no payment. LOL
