Low ph calibration

[JuanGutz]

anyone up north have some? I have 10 and 7 but I need 4 for my calcium reactor. Time to recalibrate for precautions.
Thanks in Advance!

 

[TheRealChrisBrown]

I got mine from a hydroponic store, they had the 4, 7 and 10.

 

[JuanGutz]

I got mine from a hydroponic store, they had the 4, 7 and 10.

Found a store on the way home. Perfect thanks Chris.