Ph Seems To Be Rising

[toomie]

I have 2 small fully cycled tanks for 2 of my bettas (a 3 gallon and a 5 gallon). When I first checked my tap water, it was 7.0. This was before I actually treated it with dechlorinator and used it with any fish. Previously to that I was using spring water. So now I`ve been using exclusively tap water, and since my tanks have cycled, I have noticed the PH seems to be going up. At first it was not much above 7.0, now, 3 or 4 weeks later, it is 8.2 in the 3 gallon, and between 8.4 and 8.6 in the 5 gallon. Ammonia and nitrite are both zero in both tanks, and nitrates are 20 - 40 in both tanks. Both fish seem to be doing just fine. Should I be concerned about the high PH?

If it makes any difference, I have one live plant in each tank, which came complete with their own snail colonies

Also, I have been changing the water every two weeks. IS that not enough for these size tanks? Should I be doing it weekly? I change about 1/4 of the water each time.

 

[waterdrop]

With small tanks like that it wouldn't be very hard to do gravel-clean-water-changes weekly and to change out somewhat closer to half the water rather than 1/4. It wouldn't be a big deal if you were gone for the weekend occasionally and couldn't do it. More frequent changing might be all it would take to keep the parameters more stable, without having to investigate.

Of course I suppose the first thing to wonder about is whether its possible the substrate or some decoration or something might be raising the pH. Taking a bit of substrate out or a decoration and dripping some vinegar on it to see if it fizzes is a good first test to see if there's something in there that's serving as a pH upper.

~~waterdrop~~