what affects pH?

[imma24]

This past weekend I tested the pH of my tank and it was 7.4. I added more fish afterwards and did a gravel vac/water change and tested it again a few days later - my liquid test kit showed it to be closer to 8 (although it can be hard to match the color). Could it be my tap water or the additional fish/release of waste from the vacuum? I have a 46G fw tank with 2 spotted corys, 6 neon tetras, 3 black skirt tetras, 3 zebra danios, 2 white clouds & 1 platy.

[equadean]

What's your tap water pH? Fish won't change the ph. It could either be the addition of tap water (during water change) or the hardscape in the tank like dritwood and rocks. Is there any coral chips in the tank? Coral chips can increase the ph.

[imma24]

I don't know the pH of my tap water and I have no driftwood, rocks or coral chips in the tank - I have read some postings from others that their tap water isn't suitable for their fish tank and these people have to add something to lower their pH or use bottled water. So far my fish are doing OK so I assume the higher pH isn't bad for them but I have to consider this if I want to get fish that need a lower pH. I just didn't know what was causing the increase.

[Alasse]

PH8 is no problem for majority of fish so i wouldnt stress. Excess deitris in the gravel will cause PH to drop