Go learn a little more about ppm. 0.1EC=50ppm @ the .5scale = 70ppm
@the .7 scale = 1CF. Try to always use EC, or if using PPM list it as
[email protected], or
[email protected], depending on what scale you are using, it helps to avert confusion.
So lets say you mix a new res and set it at 1.0 ec. Next day the water level is down but ec is up to 1.2, the plants are drinking water but not nutes, so top up with plain water to bring it down to say .9EC. Let say the next day it's up to 1.0ec they are still drinking more than eating..so top up with plain water to 0.8 EC. Keep doing this until your EC stays, relatively , stable compared to water usage, i try to keep it within a 0.1 range..
Conversely, lets say you mix a new res and set it at 1.0 ec. Next day the water level is down and ec is down to .8, the plants are drinking and using a lot of nutes, so top up with a nute solution to say 1.2ec. Let say the next day it's down to 1.1ec, they are still eating heavily..so top up again with nutes to say 1.3EC. Keep doing this until your EC stays, relatively , stable compared to water usage, i try to keep it within a 0.1 range.
IDK how to easily explain mixing of top up nutes..it dependent on nute strength and res volume. Let's use a 10gal( appx 38L) res for an example, all math is done by Litres. In my case i know 1ml/L of my base nutes=0.7EC. Assume a nute strength of 0.7EC, but we're shooting for 1.0EC. So to bring a res of 10 gals(38L) up 0.3ec, I'd add 1ml/L for the 2 top up gals to bring that water to the base 0.7 EC. Then I'd add 1/2 ml\L( 19ml for 38L res) for the total res volume to that 2 gals, which would equal an additional 0.3 EC/L for each gallon in the res. So at this point your 2 gals of top off should be about 1.4EC..adding 2 gals of 1.4 ec to 8 gals of .7 EC should avg out to be about 1.0EC.
.I think my math is right, someone want to review this ^^ and confirm it or not..