Nutrients build up

Hello all. Ive been growing for about 3 yrs now and i started out dwc and eventually spread my wings and set up a little recirculating system with some nets so i could scrog and all was great…but then i had my sytem torn down and put my old buckets back in action but left my reservoir hooked up with a float valve fill system so that when the bucket got to the designated spot low it auto filled back up. Everything was great…so i thought…i came in one day and two of my plants were very obviously stressed so i started combing over all of my parameters and found nothing wrong.temp was good humidity air checked the reservoir ppm… ph couldnt find anything wrong so i went about my buisness and the next day when i came in one of the plants was done it was dead and the other was like a bleached kinda colr only on the surface so im like root zone and thats where i found my issue. In my resevior the ppm was 1250 which os were i ride the last couple of weeks of flower before i flush and i also doble up on phosphorous and potassium but down inside the bucket the ppm was 3500 and of vourse when i put my eyeballs back in my head drom them popping out at the site of such a large number i dumped all the bucketa and they were all the same. My queation is this… how does the ppm go drom the reservoir 1250 to bucket …same water and all to such a large number. Any comments on that ? Thanks in advance.


I ran an RDWC system almost just like what you’re describing. One tote housed the nutrients and would just flow through pvc into 3 buckets. 2 had plants, the final one had a water pump that pushed the water through into a water chiller that dumped back into the tote.

I experienced almost the exact same phenomenon, although it was my #2 in the lineup plant who got shocked and died on me.

In hindsight, I should have known this would be what happened without wavemakers in each bucket and the tote to keep the mixture constantly mixing at all stages of the flow.

Dense stuff settles out, even when water is moving. I have a system like this designed at my job quite intentionally to allow for settling. Dirty water gets pumped into a 200 gal tank, then from that into a 2nd 200 gal tank, then into a sink, down into a 2” pvc drain with a 5gal bucket as the final settling point, then more 2” pvc to the main sewer line. The first tank obviously fills up much faster than the rest. But the second tank also accumulates sediment even when the first isn’t full, and the 5gal bucket also accumulates debris even when the other two aren’t full.

Naturally you’re experiencing this drop-out. The current isn’t strong enough in your system to recirculate all of the nutrients - some of them are settling into the buckets and just layer up at the bottom. The topmost water will continue to circulate, or in your case without circulation it will just settle and keep on settling. If the reservoir is the only thing you check PPMs in, and there is no back flow into the reservoir, it makes perfect sense that your overall ppm would rise due to the nutrients that fell out of the solution.