hey godbud ,
i happened across ppl. in arizona on ebay w/ killer prices on ppm n p.h pens . i got a milwakee p/h pen for 22.50 from em and the sell in our local hydro store for like 90.00 . w/o the proper tools you risk serious probs. such as nute lok out due to p/h flux. n burning plants from ppm being too high .
peace
crispi