Total Dissolved Solids or Electrical Conductivity Meters

[Jack Dunbar]

A good friend of mine is into Hydroponics and just today we got into this discussion of EC (Electrical Conductivity) and the use of various nutrients to come up with an ideal N-P-K for plants. He does Hydroponics and he has certain numbers that I guess he shoots for. He's going to test my water both prior to adding any nutrients (My tap water) and my FT water as it stands after I've added my nutrients and he will give me an EC number in ppm. My question is... Has anybody figured out what an ideal EC is for various plants. I know that like a squash is a hog on nutrients compared to lettuce so the EC would be higher. I realize that EC for the ideal plant in Hydroponics might be to high for certain fish in an aquaponic enviroment. My guess would be that if you had an aquaponics system that your plants were growing extremely well and you checked your EC and you got a certain ppm, it would give you something to go by. 

[Sylvia Bernstein]

Hi Jack.  EC (electrical conductivity) meters are totally useless in aquaponics because our nutrient levels aren't based on fertilizer salts, like hydro, so there is little for them to measure.  You will see false low readings with an EC meter in an AP system.

[Jack Dunbar]

Hi Sylvia. Thank you for clarifying that. That makes a lot of sense. I wish you would do a class in the NE. I would definitely be in the front row... Take care