Jacks 321 in RDWC Strength?


depends on how much light youre running. maybe on what kind of light or spectrum youre running too- my plants have been hungrier since switching to led, but i dont have any hard science to back this up. i use the same recipe and strength for rdwc, dwc, and f+d. im also running cal prime instead of normal calcium nitrate
seeds/cuts-1 ec (up to 1.3 or so by the time they move to veg)
veg- 1.8-2.15 ec
early to mid flower- 2.2 ec
i gradually reduce as necessary from there, usually ending up around 1.2 or so by the time they come down
these are provisional ec numbers only. if the plants ask for more or less at any point, thats what they get
What would be the signs that your feeding to strong of an EC? Btw do you have a thread about your rdwc setup?


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What would be the signs that your feeding to strong of an EC? Btw do you have a thread about your rdwc setup?
Too strong? See flowering plant on the right. One step away from nute burn. She's getting half the EC of all the other plants and it's still too much.


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You would think in dwc or rdwc there would be set ec to go off of?
not at all. there are so many variables to consider.

here's mine: i grow at almost 9000 ft. not many here do that. things don't grow as fast hence don't need too much nutes.

you could grow 2 of the same strain from seed next to each other and what burns one of them wont' burn the other.

bottom line: tailor your EC to your plants.


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What would be the signs that your feeding to strong of an EC? Btw do you have a thread about your rdwc setup?
typical tox or lockout expressions for individual elements, tip burn, shitty leaf posture. theyll just look butthurt in general. there are plenty of pics here and all over the net of overfed plants. check them out
i do not have a thread. there are pics of a couple of my setups here and there if you do some digging. the basic gist of my indoor is: all hydro all the time (rdwc, dwc, f+d), 3500k led+de hps, sealed rooms, a couple tents. average temp is 80 give or take, 60-70 rh. main production setup is rdwc currently. here is a pic of one of the rdwc occupied by demo (gmo x dessert breath, by genuity at chuckers paradise seeds)



I do 1.2EC in flower and 1.0EC max in veg.

Seedlings I uae my aerocloner at 0.4EC

I use their finish product the last two weeks and their bloom product first two weeks of flower.
I'm doing my first grow with Jacks and to be simple I just grabbed the RO bundle instead of the 321. One thing I noticed on the feed chart is it has a PPM reading 550 for the clone /seedling mix, and 1050 for the normal feed. Which is basically exactly what you said as 1.

I find it's pretty easy to get to the right ec PPM with less grams than they say on the bag. Is that the case for everyone? Going to upgrade to the Bluelab meters soon, I feel like it's too important to have resting on the shoulders of a cheap meter.


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No need for additional CALMAG w jacks in rdwc?
Nope. It has Calcium nitrate, magnesium nitrate and magnesium sulfate in the mix. "Calmag" is typically just a mix of Calcium nitrate and magnesium nitrate.

There's also sulfate based "Calmags". I believe Calimagic from GH is Calcium sulfate and magnesium sulfate. Cheers!


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Seems like most people keeping it on the low side.

I use jacks tap formula. I have the finish formula going atm.

My tap water is .33 ec so that is included in these numbers.

Early small plants less than 3 nodes was .500ec

Small plant .8ec

Veg. 1.1 ec or so.

Flower I was around 1.3 ec.

Late flower im lowering it down now 1.1ec and going lower.

Plants look great.

I have low humidity and hi temps.