The Lounge : Growers Round Table Discussion Thread

Thank you Jidoka. Yesterday I made a solution at 1.0EC. 100N 70P 100K 125Ca 25Mg 35S and fed at 5.9ph with good runoff. On two plants older leaves I noticed what appears as P deficiency, purpleish patch in between veins and tan dots on top of this patch. Under the leaves with this patch have purple throughout.

Has anyone seen purpling under the leaves? I always read of this as a P def but I thought I was feeding more than enough P.

I have about 1 gallon left of this 1.0 solution and will make a 1.3EC solution tomorrow morning. I also have chelated Ca that I can make a foliar.

I started the seedlings at 0.4EC then bumped to 0.7, now 1.0 and will get it to 1.3 tomorrow. I think next time I will go from 0.4 and after the seedlings are settled in go straight to 1.3.

The thing is when you underfed a plant a
Plethora of things will show up, including purple all kinds of things

If you react by changing ratios all of the reactions will lead to something else going wrong. This is how people end up chasing their tail from 1 problem to another

Given your conditions you will create a certain amount of transpiration. The trick then is to find the right ec to get enough Ca into using the best balanced formula you can.

This is a lot easier with tissue analysis but the formula I gave you will work. You want (tissue) N=K=about 2.5%. If you are lower you are underfeeding. You want Mg about 0.5% and you want Ca at least double

Or, when you see it once you won’t forget it

Anyways I would spray Ca 1x/wk at 6 grams per gal. Remember, it is not mobile so most of it is still in the roots at this point. The spray will allow you to get it in the tissue

It will look like this half way into flower

jidoka said:

The thing is when you underfed a plant a
Plethora of things will show up, including purple all kinds of things

If you react by changing ratios all of the reactions will lead to something else going wrong. This is how people end up chasing their tail from 1 problem to another

Given your conditions you will create a certain amount of transpiration. The trick then is to find the right ec to get enough Ca into using the best balanced formula you can.

This is a lot easier with tissue analysis but the formula I gave you will work. You want (tissue) N=K=about 2.5%. If you are lower you are underfeeding. You want Mg about 0.5% and you want Ca at least double

Or, when you see it once you won’t forget it

Anyways I would spray Ca 1x/wk at 6 grams per gal. Remember, it is not mobile so most of it is still in the roots at this point. The spray will allow you to get it in the tissue

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Which leaf are you sampling to be content with 1% Ca in the leaves?

I meant double k and n. 1% Ca would be a big problem. At least 5% and up to 10.

jidoka said:

I meant double k and n. 1% Ca would be a big problem. At least 5% and up to 10.

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Yer killing me... You now want K to be 2x N?

Mg@ 0.5% and Ca to be 5 to 10%.

Put down the joint...

slownickel said:

Yer killing me... You now want K to be 2x N?

Mg@ 0.5% and Ca to be 5 to 10%.

Put down the joint...

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I'm pretty sure he meant:
N=K @ about 2.5%
Ca @ 5%-10% (2-4 times K or N)
and Mg @ 0.5%

Are you doing tissue testing slownickel? If so, what are the numbers you're shooting for? I haven't been doing any tissue testing, but I like the idea of it.

Also @jidoka and hazybulldog, I saw on IG you guys both said you're doing low silica. I've been doing silica at 1% of my feed solution in coco. When you guys say low do you mean lower than that? I just read a guy on RIU that said he noticed the quality of his flowers went down with regular use (or maybe overuse) of silica in his feed solution. It perked my interest into what are "good" levels

In field soil I was shooting for 100ppm regardless of CEC. It was just a number I picked up somewhere. Maybe from Graime Sait? Anyway, I don't know if that is considered low or high either.

I was using diatomaceous earth for amending silicon in my field soil and it took awhile to show up in tests, but once it did it all showed up at once, just FYI for anybody doing the same thing. I amended my soil 3 or 4 times and the silicon number barely moved on the Spectrum soil test results and then on the next soil test the results went from somewhere around 60ppm on the previous test to 1,000ppm or something like that. So if anybody is doing similar to how I was doing it you might want to give the diatomaceous earth some time to break down especially if excessive silicon is detrimental to quality.

Lightweight said:

In field soil I was shooting for 100ppm regardless of CEC. It was just a number I picked up somewhere. Maybe from Graime Sait? Anyway, I don't know if that is considered low or high either.

I was using diatomaceous earth for amending silicon in my field soil and it took awhile to show up in tests, but once it did it all showed up at once, just FYI for anybody doing the same thing. I amended my soil 3 or 4 times and the silicon number barely moved on the Spectrum soil test results and then on the next soil test the results went from somewhere around 60ppm on the previous test to 1,000ppm or something like that. So if anybody is doing similar to how I was doing it you might want to give the diatomaceous earth some time to break down especially if excessive silicon is detrimental to quality.

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I believe that over feeding grow-sil had a negative effect on the quality of a few plants that ive grown. The growth was sturdy, healthy and pest free. However the dried and carefully cured buds were brittle, with disappointing flavor and fragrance.

Slow...what my translator Lightweight said ya fucker. It turns out it is really about getting K and Mg (and Na) to minimum amounts required so Ca can get in easier

My N-P-K-Ca-Mg in elemental numbers, not bag labels (p2o5 and k2o) is
5-x-5-7.5-1

And now ima burn a blunt

Lightweight...currently for my own grow I do not use silica. I do not want to give up P for Si

But people that pay me have this weird fear of PM. They go so far as to say you better not give me pm if you want me to pay you. So I add silicate as an insurance policy

I use agsil 16 at 0.3 gms/gal. In my experience I have been able to raise thc and oils in every case so far

My favorite silicate is Gro Sil (or something close to that). But my boys in the Springs are pretty much buying production out

Check custom hydro nutrients site. He posts excellent info on silicate if you are willing to read

https://customhydronutrients.com/soluble-biogenic-silica-fertilizer-c-1_60_578.html

I came close lol

Looking decent

Looking decent

Thanks for all the info Jidoka! I'm gradually understanding all the gems you provide.

I've transplanted my plants into the 6 inch flora flex pots and did a wet/dry cycle and had roots poking out the bottom within a couple days. I think I will transplant to their final 10 gallon pots real soon at this rate.

I still have the same kind of problem with the leaves what could be a potassium deficiency. I've noticed slight yellowing around the edges of some leaves, older ones at that. I think my calcium is fine but it's kind of hard to tell from the leaves what is going on as they show signs of maybe potassium and/or magnesium.

I'm attempting to keep the ratios Jidoka provided, and scaling the EC till I see fit for the plants. Yesterday I made a batch with the Elemental Ratio 153-120-153-188-55-75 NPKCaMgS. Micros are Mn=3 Fe=2 Zn=1.1 B=.4 Cu=.6 Mb=.1 Total came out around 1.5 EC.
3.75g/gal CaNO3
2.03g/gal MKP
2.3g/gal MgSO4

Is my P too high? I would like to raise EC even more, but my P will go even higher if I do using MKP. Could I raise my EC by using either Potassium sulfate or Potassium nitrate?

Today was the first day I switched the lighting to 18/6 so I can incorporate foliar sprays of the chelated calcium. Like jidoka said it should make things improve because it will go straight to the tissue. I'll note improvements.

Overall I think they are doing ok. Weird that two plants, same strains being fed the same show different signs of problems. For instance the picture that shows all 6 plants, the top right and the bottom middle are the same strain, Skywalker Kush. The bottom middle looks great while the top right not so much.

When I buffered the coco I just used Calcium Nitrate and Magnesium Sulfate. Could the possible potassium deficiency be caused by not using a potassium reagent in the buffering process?

That looks like a calcium uptake/deficiency issue to me.

Heres good info from Canna:

http://www.canna.ca/info-courier_calcium

Elemental that's balanced like J described but in meq that's cation heavy. Drop that calcinit a bit in the future. Perhaps sul-po-mg and tsp would be better than mkp and mgso4

Too much Mg. Get it down to 30ppm

Foilar spraying the chelated Ca helped a lot. When lights turned on they were greener than before. Definitely going to incorporate them on a schedule.

Ibechillin said:

That looks like a calcium uptake/deficiency issue to me.

Heres good info from Canna:

https://www.canna.ca/info-courier_calcium

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Thanks Ibechillin I agree calcium is getting locked up somewhere. In the pictures I posted, is it the brown spots in the margins that points to a calcium issue?

bsgospel said:

Elemental that's balanced like J described but in meq that's cation heavy. Drop that calcinit a bit in the future. Perhaps sul-po-mg and tsp would be better than mkp and mgso4

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Very interesting bsg. Could you tell me more about meq and balance? Are there formulas that help calculate that? I kinda get what you are saying and the compounds you said might offer better balance. Thanks.

jidoka said:

Too much Mg. Get it down to 30ppm

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Sounds good. Going to make a batch at~1.5 EC with Mg at 30. Should I use Potassium sulfate to lower P and fill the remainder K in? If I do this I could probably go to ~1.8EC without P going through the roof.
I also have zn, cu, and mn chelated could use to lower S. Thanks Jidoka

Damn after reading that link thats a pinpoint calcium problem!

Jidoka has mentioned before if there is too much potassium, magnesium or sodium it can block the uptake of calcium, and that Mg and P should be around 1/4 of N. Yeah the brown/rust spots are usually the signs of a calcium issue. Once the plants get into high gear and really start eating/transpiring/growing with proper nutrition it seems they struggle translocating all the calcium to where they need it even with plenty available at root level. The chelated calcium foliar (pretty sure its glycine amino chelate) seems necessary intermittently to stay on top of the plants needs. Similar situation with ammonium N foliars which can be assimilated more readily allowing the plant to focus its energy away from digesting Nitrate to other processes (Jidoka has mentioned using custom hydro low biuret urea). Fulvic acid helps with overall nutrient uptake and might be something worth considering adding to feed and foliars.

Elemental ratios imo 5-x-5-6.1-1. A 1.5 EC with source water at 0.2-0.3 is gonna be N approximately 123

So high P would be:
3 gm/gal cano3
1.64 mkp
1 Epsom

If you really want low P the extreme would be P=Mg for me:
3.65 cano3
0.5 mkp
1 k2so4
1.2 Epsom
And yea this has 150 N but I didn’t want to do math and I remember this one

You can also use agsil 16 if you want...just do the math so k still = n

Or Anywhere in between and there are tricks if you want higher P or Ca

Here is a higher Ca and P room with 2.5 weeks to go



Number 1 though is what Slow said day 1 he showed up...it’s the Ca. With salt that means do not use any more Na, K or Mg than you absolutely have to

If that leads to excess Ca it is stored as insoluble Ca Oxalate. Sucks if that happens in your kidneys but just happens to make weed smoke smoother