Get teh liquid pH indicator drops, which are way more accurate than a metal probe soil tester, and cheaper too. REad the flushing sticky in 'problems; for how to use them.
In emergencies, you can use cider vinegar to lower pH, but I would straongly advise actual horticultural ph down from the hydro shop. They also sell the indicator.
There are many reasons your leaves could be curling; can you post pics and fill out the form in 'problems'?