Ph Changes After Water Changes

[tttnjfttt]

I've always known that my water has a low KH, but now i'm a little concerned. My water comes out of the tap with a pH of over 9 +++, so hihg the test kit doesn't measure it. My tanks used to stay around 8 (back in september), but the past two weeks they have been staying around 7.4.

My concern is when i do water changes, the drastic change i'm getting in my pH. After my water change yesterday, my pH had jumped up to 8.0. This morning, i tested it again, and it was back at 7.4

Does anyone have any advice for me on waht to do to minimize this change? Storing the water elsewhere to let the pH drop won't work. I was thinking of maybe adding some crushed coral to the filter to just keep it up around 8?

I currently have bettas, tiger barbs, zebra danios, clown loaches, an opaline goruami, and a red tailed black shark.

 

[love_fish]

The tap water prolly has a small amount of buffers in the water to keep the pH high. You could run some coral through your filter to keep it raised like you said. I tihnk you can also add baking soda to the water you're using to change because I think it acts as a buffer.

 

[tttnjfttt]

The KH (buffering capacity) is actually really low in my water. It comes out of the tap reallly high, higher than the high range pH test can check for.

Tap water - 9+

tank pH before water change - 7.4
tank pH immediately after - 8.0
tank pH 24 hrs later - 7.4

Because the pH is dropping that significantly from 9+ to 7.4, that shows there is a very low KH.

The large changes is what i'm more concerned about. Would my fish be ok with the crushed coral?

 

[love_fish]

Yea, I use marine aquarium rocks like coral in my tanks, and they work great for adding buffers. So you'll be fine IMO.