my vote would be to addback fresh water with half strength nutes until your reservoir change. If 1350 to start is strong enough, I would bring it back to at least 1200 after it dips down to below 1000. I have never heard of someone over-feeding with a constant ppm of 1350 though.

Is your float valve connected to a water source that refills your reservoir with plain water when it gets low ?

Is it possible that you can have more nutrient solution in your reservoir, so that you dont need a float valve triggering more and more plain water diluting your reservoir??

I wouldn't schedule a reservoir change every 4-5 days. That will get old really quickly and you will kick yourself if you later find out that it would have been better to change once a week to two weeks with a few different techniques.

Ask Zandor, he will shed some light over to you.
Stormcooker Reviewed by Stormcooker 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