Can someone please help me with PPM

[jer001]

first time grower and I do not understand what the deal is with PPM. How do you measure it, and so on.

Thank you

jer001 Reviewed by jer001 on 10-27-2008. Can someone please help me with PPM first time grower and I do not understand what the deal is with PPM. How do you measure it, and so on. Thank you Rating: 5