late flower reduction of Calcium to 0 ppm and Nitrogen cut in half to 65ppm using Jacks part A of 321 fame.

Missouri Green

Active Member
so I was reading an article by someone... who recomends cutting Ca to 0ppm after week 5 if growing in any "soil like" substrate...

I had been growing for some time using 450ppm tap water with high calcium and alkalinity... on top of that i was using Canna Coco which already has lots of Ca.. on top of that i was running cal mg too... i have long suspected using hard water was not doing my final product any good.. bud always looks great but it rarely smokes great.
recently i purchased a RO800 system with plug and play filters.... I started this grow with jacks 321 intending to run just that straight through, but apparently I like to make moves... switched over to Jacks RO formula around week 2/3 of flower... now approaching end of week 7, just ran a PK13/14 boost during week 7 but i had CaMg in there at high levels and after reading this article I thought to myself... lets go 0ppm cal from here on out. I started fiddling with hydrobuddy but just can't get much to work out aside from running Jacks part A all by itself.. no Calnit and no epsom salt.. I end up with high sulfur at 126 ppm but 0 Ca which is what i was shooting for. probably got a little Ca left over in the coco and probably tuns in the plant...

here's my old numbers roughly and my new numbers..

i run at 1.5 ec roughly so all ppms are at 1.5 ec roughly

old: 125N, 55P, 176K, 63Mg, 120Ca, 37S, 2.49Fe
new: 66N, 70P, 285K, 83Mg, 0 Ca, 112S, 3.96 Fe

anyone see any problems with my approach? this strain is rumored to go 70-80 days. i have not really seen many pistils turning yet so I figure im going at least 10 weeks with a probable 14 day flush (ish) i've got about half/third of the pot as coco... plant is deep green but not many leafs (defoliation), buds are small-medium just as seller description says and very frosty. Tahoe Animal from Greenpoint.

have some ammonium sulfate coming just in case my plant fades too fast.... my S is already pretty high adding in the ammonium sulfate would put me up around 175ppm S :) . maybe fun experiment and I love the smell of ammonia in herb. this cat piss strain i had 20 years back was the best... also its believed that at low temperatures ammonium is an OK option for hydropoinics as oxygen and sugars are more available int he rootzone as ammonical nitrogen needs special processing that nitrate nitrogen does not... and i'm in the process of lowering temps as we speak ... being winter the rootzone is always under 70 probably closer to 65... fresh air comes in under the plant and gets mixed as it rises... just under the lights is always the warmest area which is currently at 75 degrees lights on..

I will say that part A has all the micro nutes for the 321 mix and I'm not running all the bells and whistles i was using for the "old" bloom formula which mean my proportion of micro's is as strong as it can get... 50gr part A in 10 gal vs 33g RO mix plus extras. you can see it in the Fe numbers..

thoughts appreciated ... I'm thinking I will be just fine.... considering im 1-2 weeks from flushing here she is...

after reviewing still shots from my esp32 cams she is plumping up since the last 3 days.. keep pumping baby.
there is nothing better than having cams in your grow.. hit "get still" and watch them move since the last time right on your laptop/desktop.. keep a file called plant by week and send a screen grab to that file once a week.. its super helpful in getting a feel for whats actually going on with the plant because by eye its sometimes hard to tell because its so slow.
Last edited:

Missouri Green

Active Member
Doin just fine.. tops look a little foxtaily, light turned down a little and temps are down too. 71f at the top 68 down low, continuing to fatten up.. water and nutrient uptake both reduced. 2.5 weeks to go ish. gettin stinkier. deep green top to bottom, no fade in sight...
Last edited:

Missouri Green

Active Member
She looks pretty happy. Your in pure hydroton?
no its about 3inches of hydroton on the bottom, then stainless steel screen with 5 inches coco/perlite 50/50ish on top of that, then about an inch of hydroton on top of the coco inside a 10 gal grow bag inside a black plastic bin with hydroton surounding that and protecting my drains... we could call it 30hyroton/30coco/30perlite if we wanted to, though the layers are well seperated... it drains extremely well
I top feed anywhere from 15 off 1 min on, to 4 hours off 5 min on... depending on me and ph and what the plant says...
I also have two drains.... one has a riser. been using that lately at 3 hours off 5 min on.... the 2-3 inch riser holds water for about 2 hours then it goes dry .... at 3 hours i water again and repeat that process. ph and plant says that that works. sometimes i get a ph drop and i go "ah shoot that might be root rot!!!! maybe give it more air?" but playing with power Si and microbes who knows whats going on.... i just get scared and go "water less idiot!!!" seems to work.
Last edited: