TDS meter on amazon:
About the PH, EC, TDS Meters category
Cheapest way to monitor ph/ec etc. when beginning?
Need a ppm pen whats a good one
Any advice is welcome
Need help with my plants
White stuff around roots after changing nutes
I have this Etekcity one for $12.99. Have had good results.
@MacGyverStoner Just out of curiosity have you had a chance to use either one or both of these? Thanks