Are you saying to stop using the peters and just use the salts? I was using MKP for my P, and a little K, and getting the rest of my K from the SOP. I use Epsom for all of my Mg, but thought maybe some of my issues were from having S near 150 ppm. I know you said you like to be vague on things on purpose, but if I should aim for 180+ ppm of Ca, can you suggest a starting point fo N please?
I re-read, some of your pryer posts, and noted you suggest a 1:1.5-2, N to K. Does 125 ppm of N sound like a decent starting point?
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Ca edta will just complicate your life, particularly supplying that much in the edta form. It will outcompete and antagonize just about every other cation. Calcium Acetate will work out much better for your purpose, I import it direct personally, but bulksupplements has good pricing.
Yes, drop the peters. We want to get the Ca:N ratio as high as we can. The KNO3 in the peters works against that.
S is the one thing you donāt have to worry about oversupplying and causing antagonism with. Iām not at my computer, but I think mine is 200ish.
Donāt be scared of too much N. Right now today my flower canopy is running at 148N. Itās higher in the summer and lower in the winter since I have variable (sun) lighting. Iām currently managing indoor canopies with anywhere from 135-180N. You get screwed by N as well as K when they are supplied in excess in relation to Ca. Either use greenhouse grade cal nitrate, or add cal acetate to hit cal prime ratios, then you can modulate the cation ratios to supply sufficient Mg and K without overly antagonizing Ca. Those ideal cation ratios vary considerably base on environment. You can also hit the same tissue analysis numbers with wildly different nutritional ratios.
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Then back to the drawing board it is lol! Honestly, thanks for taking the time. You seem to have a lot going on, and I appreciate your help. Iāve learned a lot already.
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Within reason (ec around 1.5-2.5) the ratios are honestly more important than the absolute concentration of any one ion. As a base for flower I currently start around 140N, 75P, 275K, 175Ca, 60Mg and work from there guided by tissue analysis and brix. Depending on environment that amount of K may overly antagonize Ca, if that happens the most obvious sign is dark foliage in flower, in that case you would run less K. One of the most egregious mistakes I see in the industry is seeing that dark foliage and assuming itās excess N, then reducing cal nitrate which brings Ca down and makes the original problem worse. Give your changes at least a week to take effect, a lot of folks I encounter are changing things so rapidly that they never know where they actually are. You will be amazed how much changing K and its ratio to Ca and N can change morphology.
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Iāve been guilty lately of changing things so quick, Iām not sure whatās working and what isnāt lol! Iām going to implement the things you suggested, then take a step back and observe.
Iāve been doing exactly this. Iāve always been of the mind that dark foliage was the result of excess N. The Sativa hybrids last run, were also doing this weird, not tacoing, but leaf narrowing thing that I thought was from to much N. I cut the Cal Nite, and started supplementing with the Ca EDTA. The narrowing got worse.
What would you say would be an acceptable amount of Ca EDTA to use until I can order the Ca Acetate?
It really shouldnāt be necessary. At most 15-20ppm Ca over what the cal nitrate provides. That will get you to cal prime ratios. You canāt really over fertilizer Ca, the only bad thing it really does is antagonize K, but it sure gets pretty damn expensive using edta or acetate.
Ca uptake should really be modulated by augmenting with the cations it competes with, mainly K. A $20 refractometer is a priceless for accomplishing this.
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If I understand correctly them ratios are close to the ratios of the analysis I posted?
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I made up a recipe last night on paper, using what I have on hand. Iām at work right now, but if I remember correctly, to achieve 130 ppm of N, and 163 ppm of Ca, I think it was 3.25 grams per gallon of regular Cal- nite. To boost the Ca to close to 180 ppm, I would add I think it was 1.1 grams per gallon of the Ca edta. Donāt quote me on those exact weights because I donāt remember right off hand, but I know it only added 19 ppm of calcium. My target ratio is, for veg right now,
N- 135 ppm
P- 65
K- 190
Ca- 180
Mg- 60
S- 80
Si- 52
Fe- 2.8.
My actual ratio came out within +/- 5 ppm of my targets, except S which is past 120 ppm, and not including micros of course. Please feel free to critique those ratios as you see fit.
Does your calcium edta raise your nitrates?
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I have been checking out the refractometers. I see prices all over the place. From $18-$300+. Can you recommend a good one in the $100, give, or take range?
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No. Only adds Ca.
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Itās not too far off. You could hit really similar numbers by slightly changing the athena ratios. Itās also just a starting point. In coco, opās media, I would expect to be reducing the K a little bit, to around 240-250 to get everything at a happy brix, but that is very environmental dependent. With athena if we brought the core up to the N and Ca numbers Iām talking about and kept the bloom right there, I would expect to see an Mg problem. But if you ran something like 3.5g core, 4.5g bloom, 1g epsom that would solve that problem.
Edit: both athena facilities that I have looked at with a refractometer and laquas show Ca to be the limiting factor, thatās what Iām basing my opinion on. A bit more Nitrate and Ca to help Ca come up and a bit less K to reduce e it competing with Ca.
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Bump cal nitrate to 3.5. Are you sure that 52Si is Si and not Sio2? 52 is pretty high, not a lot of reason to go above 20 Si. Even for veg, you will probably want that K around 210, and then bumping it up again in flower. I do like the strategy of starting low on K, itās easy to fix a K deficiency, itās a lot harder to fix a Ca deficiency.
Refractometers are something where spending a bunch of money isnāt necessary, the way they work is stupid simple. Just get a scale that goes up to at least 20 and has ATC. I have a Reichert and Extech in my bag, but leave $20 amazon ones everywhere I work. The Extech, even its case looks exactly like a cheap one with an Extech sticker on it, so donāt waste extra coin on that one. As long as it reads 0 with ro water and roughly 10.5 with coca cola itās good to go. The more important thing is getting a beefy stainless steel garlic press to juice samples.
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Iāll have to check out the Athena site. I only heard of them recently, and havenāt researched theyāre nutrient lines yet.
They go deep for formulation. Their polyphosphate for pH control and cleaning lines isnāt well known yet. Itās why that have so much intrigue with the DIY crowd.
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I havenāt used Silicic acid yet, only Potassium Silicate. 1 ml per gallon of Ro, is supposed to be approx 9 ppm of K, and 26 ppm of Si, but when I measure Ec, itās only 11 ppm total. I read on Manixbotanix that Si is shown to be beneficial at over 50 ppm. Not sure how true that is though.
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Grant from Manic Botanix is legit. I try to talk to him once a month.
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