OK,

so my 50% nut solution when first made reads at around 1000PPM.

but when the res gets down low, from say 6 gallons to 2 gallons, i take a reading and it shows up as 1300PPM?

is this normal? i thought that it was supposed to go down as the plants use it?

also, if i take daily readings, it would go down down down, then as its near empty, it would be high

im thinking maybe particles from the rockwool?


Last thing, what can i do about not having green fungus or whatever its called (maybe its mold) thats forming on the drainage tray?

(its a big bin that was cut down to only be 10inches tall, and during veg stage, i have a drip-like system feeding it 4 times a day, and then when they go to flowering, it gets changed to a ebb and flow setup)
zero0ne Reviewed by zero0ne on . odd TDS readings... OK, so my 50% nut solution when first made reads at around 1000PPM. but when the res gets down low, from say 6 gallons to 2 gallons, i take a reading and it shows up as 1300PPM? is this normal? i thought that it was supposed to go down as the plants use it? also, if i take daily readings, it would go down down down, then as its near empty, it would be high Rating: 5