Addback Calculator: this formula is responsible for calculating the approximate dosage of nutrients needed to be back up to regular levels.
This is not my formula, however brilliant, and I don't remember who/where it came from, only that I had it written down for reference. So mad props to the source.
((target – current) / target) * _ ml per gal * _ gal reservoir = dosage
target = what you want your ppm to be
current = what your ppm is at currently
_ ml per gal = whatever feed dosage you're using
and so on
You would do this for each separate nutrient. Hope this helps. Also, don't forget about pH.
Cheers fellow growers! I'm starting my first hydro grow with a bubbler system, i have 10.5 U.S. gallons in the tote.I will be growing two plants out of it. I know if I measure my water and my ppm is too high, i can easily dilute the solution with more water. But if my solution is not strong enough, and it's not time to change the water, how do i go about calculating how much nutrients I should add to bring my solution back up to par? An example would be greatly appreciated.