PH Balance, and a few other questions about chemical testing.

[Jaysn]

My pH is comes out of my tap at 7.6 to 8.0 and settles down to around 7.3 pH. I can't really explain what makes pH change like that, but I do not think its unsafe for your fish.

The pH change is caused by CO2 outgassing from your tap water.

 

[quadpants]

CO2 outgassing would raise pH not lower it.

 

[musho3210]

25% per week is a good one, of course nothing wrong with 50% a week. Im pretty sure chlorine and some other things in tap water raise ph, but when using a dechlorinator or sitting water they leave which in the ends lowers the ph.

 

[musho3210]

CO2 lowers Ph, O2 Raises it

How do you edit, whenever i try it doesnt work

 

[quadpants]

The CO2 content varies between water companies, but after it leaves the tap it will stabilize around 3 ppm after a day. So if your tap water has lots of CO2 in it, it will outgas until it is lowered to 3 ppm and the pH will rise accordingly. If your tap water has less CO2 than 3 ppm, the pH will drop as CO2 is absorbed.

That is why if you want to test your tap water's pH you need to let it sit for 24 hours so the CO2 reaches its normal levels. Testing it directly out of the tap is not accurate at all.

 

[Rbishop]

To stay with the OP's topic, do a water hange the day you leave, regardless of the readings. For two days you will be fine. Do not even feed the day before, wait till you get back.