Tested ph yesterday and it was close to 8, tested it today and it was close to 7, what could cause this?

[badaboom423]

I added some soda ash to increase it just now, will test again in a few hours. Is it normal to see such drastic changes day to day?

I did add some nophos yesterday (I know I shouldnt care that much about high phosphates,but had already bought it), can that lower ph?

 

[mknauss]

No. The only way pH drops is due to chemical addition.

Try to not use chemicals to raise your pH level. Aeration will do it naturally.

 

[Donldson]

That's a pretty big bounce. Do you have a TA reading from before the soda ash? If not, what is it currently?