What PPM for marijuana


A question from a fellow grower:

What ppm should I be at mid flowering.
I’m using GH gro,micro,bloom,florabloom,flora nectar in 100pm tap water at 5.8ph.
I’m using a 30 gallon tote so the roots can hang and I have it flooding
Every hour. Plants are in 6" nets with hydroton. Using 600watt HPS and several 5500K CFL lights under canopy.
I was at 1400ppm and just replaced all the water. I keep reading JH likes
Low level nutes and want to be careful since I have about 4-5 weeks left. I’m at 700ppm now at a 1:2:3 ratio.
Any input and wisdom would greatly be appreciated.


I run 1500 ppm in flower using GH 3 - part.

I use an advance d formula though. .5 of Gorw 1 part Micro, 1.5 Bllom. That would be 4ml-8ml-12ml per gallon


I’m starting 4th week of flowering. Currently the pH is 5.3 and TDS is 1640 ppm (using GH Grow:Micro:Bloom ratio of 1:1:1). I plan to adjust this ratio to 1:2:3. Should I use un-nutritioned water for a week before I transition to this higher Phosphorous, lower Nitrogen ratio. I read on one of the blogs here that soil bassed plants should use untreated water between weeks 3 and 4…I think to reduce some of the Nitrogen in the plants?


To fellow grower…If you are using Bloom additives with GH 3-part. You should not be using the 1-2-3 mix. That is for use when you DO NOT have bloom additives to give the plant more potassium.

I would eliminate the grow, and use 0-1-2. Additives 1st, then Micro and Bloom. I would run 1400-1500 for the next 2 weeks, then reduce ppm to 1200 to ease into flush and finish; Allowing the plants to use the stored nutrients which will result in a better tasting yield.