Realllllly low pH in QT tank...Can't figure this out

[GreenSpottedPuffer]

Originally Posted by Johnny Reefer

What's your ammonia, nitrites, nitrates at?
Are you doing frequent (emphasis on the frequent) partial water changes?

0,0 and 15. No frequent changes, just once a week. This is a cycled tank, not just set up last minute for new fish. Whats the emphasis on frequent for and what does it have to do with the PH?