They sell very cheap water PH test kits at the Hydro store... 3-12 dollars
You can also get a test kit from Home Depot in there pool supply section.

http://www.plantitearth.com/store/pr...id=63&catid=65
this is a water ph tester

If you post some pictures I will be a ble to tell you what is wrong...
Are you over watering? Are you letting your soil dry out before you water?

: )