Well, the PPM is over 2000 and the pH is 5.48. Added 10 gallons of water - the tank is nearly dry. They are sucking it up!
It's just crazy, isn't it!?!? I'm glad I went and checked the res - almost put it off until tomorrow.
I start the week with four gallons per plant. I check before lights out, and again at lights on. If I were to skip one or the other it would be alright. I could not skip two in a row with out disastrous consequences occurring with my ppm.