I have a couple GT series NFT systems and was reading about draining the tank every week. Does this have to be done every week or every month since im measuring the EC and topping of the tank with water and nutrients, i calculate how much water i add to the tank and i put in fresh nutrients for the emount of water i added. Should i keep up with this method or should i drain the tank every week and put in fresh nutrients. I appreciate your help. also whats the difference between and EC and a CF meter? NVM found the answer EC and CF (Conductivity Factor) are easily converted between each other. 1 ms/cm = 10 CF
The problem with measuring only EC/PPM, is that the plants take up different nutrients in different amounts. If you don't refresh the solution, and just top off with the nutrients you use, you will end up with an excess of certain nutrients in the solution, which may cause other nutrients to be locked out. It's the same concept with my saltwater reef tanks, I can keep topping the water off to replace the minerals used by the corals, but the minerals not used will build up and cause issues.