Hi, after mixing a fresh reservoir of nutes (in an aero system), the ppm was 1350. 24 hours later, it was just under 1000. Next day, it was under 800 â?? a pretty weak level for foot-plus plants. Iâ??m a complete newbie to hydro, so I was wondering: should I be replacing what they eat everyday (bringing the ppm level back to 1350 daily), or should I let the plants drain the drink down to [whatever it is after a week]?
I read on this forum one opinion that replacing what they eat is good. But logic is also telling me that since they consume different nutrients in different quantities, there would be no way to know what balance of nutrients to add back. For instance, if the plants dropped the reservoir ppms by 300ppm, and almost all of that was N, Mg and K, but almost no P,K, or Iron. If one were to add-back using the same bottled nute formula, then the depleted amounts of N, Mg and K would be replaced, while the [unused] P,K and Iron levels would be doubled â?? not a good idea.
On the other hand, if I leave the reservoir alone for a week, after a couple days when the ppms drop drastically, then foot-tall plants are getting a nutrient-strength right for clones.
My only solution to the quandry is to change the whole reservoir more frequently, like every 4 or 5 days instead of 7.
What do you all think about this? Or, what do people in the â??real worldâ?? actually/usually do?

P.S. The reservoir has a float valve and never gets low on water, so the observed ppms arenâ??t being affected by the water level dropping.

peace
growinit Reviewed by growinit on . Top off res with nutrients or just water? Hi, after mixing a fresh reservoir of nutes (in an aero system), the ppm was 1350. 24 hours later, it was just under 1000. Next day, it was under 800 â?? a pretty weak level for foot-plus plants. Iâ??m a complete newbie to hydro, so I was wondering: should I be replacing what they eat everyday (bringing the ppm level back to 1350 daily), or should I let the plants drain the drink down to ? I read on this forum one opinion that replacing what they eat is good. But logic is also telling me Rating: 5