Jack's vs Chemgro, Nicky's Experiment

Hello Friends and community members.
This is going to be my flawed experiment of Jack’s vs Chemgro. Two different nutrients Wich are both three part dry salt based nutrients provided by American hydroponic companies which have been around for a long time, to boot the price of these nutrients is outstanding.

I have used chemgro for a bit over 2 years now as jacks is harder to get into Canada probably due to some ingredients in the main fertilizer that is banned at our border, however I have found a source and after me and @imSICKkid have been recommending jacks for some time it seems to now be a very popular option within our community for many reasons.

Hopefully @imSICKkid @Hellraiser @Myfriendis410 @Not2SureYet and others running it can help ensure I am running jacks correctly from here on out as I may be a bit hazy on some things here and there about the amount to feed in the early stages.

I will be following chemgro’s feed chart but I have my own version with a couple notes and I have changed the PH levels after much of my own research.
The original feed chard here

Followed by my modifications (I’m actually still narrowing in the exact amounts needed per 5 gallons to reach the target ppm, because I haven’t kept good records about that before and just added a dose or diluted to appropriate ppm)

Jack’s has a simple formula of = 3.6/2.4/1.2
That is 3.6g Jack’s 15-12-26, followed by 2.4g of calcium nitrate and finally 1.2g of magnesium sulfate per gallon.
So for me the formula is 18/12/6 per 5 gallons
To my understanding this cna be fed from day one to harvest, however the ppm is quite high in my opinion so I wanted to see what the others have been doing in the first 3 weeks of growth. Chemgro has said 400-650 in the first 3 weeks before shooting up to 1100 but when I mixed a full batch of Jack’s it came in at 1200ppm.
So the very first feed was done at 650 for even sake.

Unfortunately I have had some extremely frustrating bad luck with seeds over the last while so the plants are not all the exact same age but this is close enough to be not an issue as we will worry about final bud quality and yeild for the verdict.

The experiment will be conducted in a 4x5 tent, using a 320xl hlg v2 3000k and a 240w kingbrite 3500k ir/uv/red (currently using only the 3500k with uv/ir/reds turned off until post flower stretch)

The seedlings were planted in nursery bags filled with pre buffed and ph’d coco them mixed with perlite for a 50/50 mix.
They will soon be transplanted into 5 gallon fabric pots of the same medium and when large enough have the autopot system turned on to allow bottom feeding from a reservoir.

Two amnesia haze (AH) freebies from seed city will be going up against two monster Bruce banners (MBB) with one of each on jacks and one of each on chemgro, running two different reservoirs. One of each genetic will be under each light as well so as to try and keep the results as close to accurate as possible (really wish I had another 320xl but I don’t have the $ for that).
I have some other plants that will soon be culled but the jacks will be running a green crack photo in a 3x4 tent in my grow room as well. Yes you heard me correctly Nicky is finally going to grow a photo, so I will have to inspect my tent for light leaks and LED’s soon and patch or black out anything.

I had planned to run completely different genetics but like said above had some serious issues and burned through about 20 auto seeds before getting these, extremely rare for me so not sure what I was doing wrong but moving on.

As always my plan is to fim at the 4th or 5th node for the autos.

I have a light breeze on them as of today and have the temp set to 25.5c with a spac heater on a temp controller. Humidifier is running full blast but humidity is on full blast but will doubtfully keep up with the dry heat from the heater and my dry environment. So not ideal VPD but managing best I can.
This grow is reminding me why I like to start seeds while one of my tents is still flowering, as it keeps my room nice and warm without having to add dry heat.

Yesterday was the first day for the MBB and the GC with leafs open above ground.
While the first day above ground for the AH’s was March 24th, the MBB are growing with much more vigor though so soon they will look similar in size I’m sure.

Both systems will be running Agsil16H potassium silicate and Fishsh!t microbes.

Any input as to what I should be feeding on the jacks side from now until full strength would be ideal. Should I slowly adjust it at the rate of increase as my chemgro or should I feed light for a week or two hen feed full or should. I just give full from the start.

Anyone with any input or suggestions please chime in, this is not a clone large scale experiment but that just isn’t in the cards so I will do this style of grow for two grows in a row (different strains) and see if anything sticks out.

@dbrn32 @Covertgrower








What a Photo! I figured by now that was a curse word in your mind. Here & watching


Green crack is a strain I’m thinking my dad is really going to like, however it’s actually sorta hard to come by few breeders have it in an photo and even fewer in an auto. I was gifted a green crack photo fem from my mentor and family friend 2 years ago Mayne 3 now and so I decided I would pop it. Crop King is not know for great genrtics but they are okay I Geuss average to below average stuff.
Otherwise it’s fastbuds for the omly auto available to my knowledge, while the other green crack photo gems are from Humboldt seeds or growers choice.
I’ve heard very mixed reviews from people growing out both versions of the photo and I would assume Canuck seeds, crop King and other seed bank has merely taken these seeds and bred it to slap their own label on it.

As to which genetic is the best and which do I want to grow out again in the future I’m still Unsure, my dad being 79 this year really enjoys a energy buzzing sativa and this pretty much the only high energy sativa have found. While. Super lemon haze and the diesels are good strains they don’t pack the energy boost to my understanding and according to the online databases at places like leafly or strain compare.


I’ll be watching…im using Jacks on everything now. However I start and stay in FF (haven’t made the switch yet to coco) soil and start feeding at full strength 6 weeks into veg as growth slows.
I also use Tribus…original and bloom now too.
Thanks for the tag…ill be here!
Goodluck to the girls!


71 here & I just got some Green Crack & Durban Poison 2 days ago. Ordered a 5x5 tent yesterday & when it gets here I’ll set er up & give them a try. In your 70’s any energy will help. Had to give up coffee cuz of blood pressure issues. Going to try Jacks when I run low on the GH I have.


I’m still stuck with FF. I bought it by the gallon when I started growing again. Was thinking about going with Jack’s and will be interested in the results of this thread. :slight_smile:


Forgot to tag you @MidwestGuy so many to remember sorry.

@pillsbury who’s the breeder of the GC?

@abouttime sounds about right if in fox farms soil. Ide be doing the same if I was still growing in soil, I. Used my chemgro when in soil so. Doing the exact same thing as you. 4-6 weeks I would feed depending on run off.


ILGM is where I got it, I don’t know if they use other breeders or not. Will your auto pots handle a photo O.K.?


Glad to be here. The nutrient debate is a good one. Set to watching.


Niiiiiiice! This should be a very hype thread! Looks to be a good one :+1:


Saaweett… I actually got a white crack auto gifted from @Gremmall … hey grem where did that white crack come from… set to watching :nerd_face::popcorn:


Out of curiosity, I used jacks full strength when my soil still had 2500ppm in it and didn’t burn the plants at all. The stuff is gentle. Excited to see a side by side comparison.


Well original Green crack was a clone only strain so many who were in the game long ago eventually received one of these clones and a very few ever made seed from it, others bred their own using the lineage history or some like Canuck always does it takes a week established breeders genetics and just makes seed from it then sells it on their seed bank site at a discounted price compared to the original breeder (shady AG and I don’t support Canuck seeds or true north at all)

@MidwestGuy is a good topic for sure. Recently I was in touch with a Lotus nutrient distributor who has a sample waiting for me to run two crops with against the winner.
So I’ll do this Jack’s vs chemgro at least twice and then go from there, if I want to keep doing it until. I can tell a difference I will otherwise I will pick a winner and then face it off vs lotus to find my favourite dry based inexpensive nutrient line.

@Jackie_Daytona new journal. Here


I wish you did this 6 months ago, lol. I’m sitting on a pile of Chemgro now, but I guess I’m motoring through it faster than I expected. I modified the ratios to bias the Chemgro the second half of flower.

Looking forward to seeing the results, I’m pretty happy with my results but I’ll switch if you show a noticeable difference.


I’ve been feeding full strength jacks since i planted the seeds in coco per @Hellraiser advice and my ladies are looking good.


Set to watching Brother! :sunglasses::v::call_me_hand:


Sweet, watching, love experiments. I’m planning a nute experiment myself on an upcoming grow - Jacks vs Advanced Nutrients with my Cherry Ice Cream clones. Still have plenty of AN nutes, might as well use them up and see how the plants look side by side.