actual footage of me partying on Saturday night
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I suppose it wouldn’t help my case to mention that I was also watching coverage of the speedchess championships on youtube (and found it pretty exciting). Weed, chess and plant nutrition on a Saturday night… how my life has changed over the years. 
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One more idea. Flowering I think increases demands primarily for K and Ca. So one thing you can do is not touch N, but change the ratio of anions away from nitrates.
This is potentially the natural home for potassium sulfate and calcium chloride. Adding chloride will have the effect of diminishing the absorption of other anions. So you could achieve lower N absorption by leaving it alone, and diluting it among other anions. At the same time, you can keep the K:Ca ratio from going out of control by increasing both. Just keep a base mix at a certain EC (say 1.8), and then add additional EC (+0.2) through a Potassium Sulfate / Calcium chloride bloom booster.
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This base mix could/would be acidic and could supplement trace minerals?
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Yes, you can control the initial acidity through balance of MKP/Grow Clean and DKP. MKP is acidic and DKP is basic. If you use them in roughly a 3:1 ratio, it will end up pretty close to the pH you want.
Then with the “right” amount of ammonium, you can combat the rise of pH in the rhizosphere and in recirculating solutions.
Trace minerals need to be mixed at acidic pH, and could be included. Some 25% of Iron EDTA I’ve read becomes quickly unavailable if the pH rises to 7. DPTA should be a little better, but the other chelated trace probably also have similar restrictions. I think it’s best to never let them experience a basic solution.
I think I’m getting close to determining the next nutrient solution I want to try. The only outstanding question I have is how much ammonium to try – somewhere in the 5-15% of total N range, but I’m expecting substantial differences in that range.
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I was always of the mind to just slowly back off the Calcium Nitrate to the point of not adding any and, then supplement Ca with something like Ca Acetate. I’m slowly finding out you can’t really replace all the Ca in a mix with stuff like that. I like the idea of keeping a base mix and bumping up the different anions.
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Wait… micros are supposed to be mixed at an acidic pH? What can u mix them with?
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I don’t know how I missed your whole right up on cation, anion balance. Fantastic right up. Definitely a lot to take in. I will admit there’s a lot I don’t understand about it but, I’m desperate to learn.
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This isn’t a white paper or anything, but mirrors my experience with using “solution grade” gypsum for calcium in flood and drain hydroponics.
At 20C (68F), calcium sulfate dihydrate – the form most commonly available – has a solubility of around 2.4 g/L. In practice this means that you can have up to around 550 ppm of Ca in solution from calcium sulfate dihydrate before you observe any precipitation happening.
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I think the chelates are all more stable at low pH <7. Iron DPTA is probably fine at 7, but I wouldn’t go above 8. I’m not sure about the other EDTA micros, zinc, etc.
Usually it’s not a big deal because they’re already in mixes like Jacks that are at least a little acidic. Those usually mix to ~6.2-6.4 with my water (which is pretty soft ~0.1EC).
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That’s cool, so even though you can’t make a stock solution from it, there’s at least enough solubility to put plenty of Ca in solution. Does it fall back out at all if you leave it for several hours? I see the article advises that it can take a long time to dissolve.
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I’ve mixed a tablespoon of DownToEarth/BAS solution grade gypsum in a 5 gallon bucket for maybe 2-5 minutes and it’s pretty much all dissolved.
I haven’t had any precipitate back out either after at least a week of sitting there nor in the reservoir…
I started originally by adding it after the maxibloom but switched to adding it before and things have been great for the most part. I’m running different things on the same feed so you do what you can 
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@lefthandseeds. What do you think a good finishing mix should look like? For say around Weeks 6-7 for a 70 day strain? I’ve dropped cal-nite to a total of 11 ppm of N and, now in week 7, have begun to drop K from a max of 289, now down to 229. I’m starting to get a K deficiency. Ca is at 154, so not sure if that has begun to antagonize the K. Mg is at 73. What would you do in this situation? Raise K to compensate for the deficiency while adjusting the Ca, and Mg to keep a 3-2-1 ratio, or continue to lower K being that everything will be ready in another 3 weeks? Was going to do a 2 week flush with added fulvic and micros, because I read somewhere that buds with a higher terp profile, had a higher concentration of micronutrients in the tissue samples tested. I’m thinking that might not do anything because, don’t micros need some P in the mix in order to be properly transported through the plant? Sorry for the long windedness. Trying to figure this out and not sure where to start. 
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I think some schedules do things differently than others. Probably the most common I’ve seen is to raise K the further into flower you get. I think it’s usually fine to put K in the range of 3:2:1 to 4:2:1. I’d probably trend toward the latter toward the end personally. 230-300 can all be reasonable numbers for K, depending on the strain. I’ve never tried really cutting the N that far. I’d think that’s ok after the buds finish swelling though. I’ve read several sources that say to keep N constant through the entire grow, but a lot of what nutrients you provide at any stage depends on what you fed previously and what the plant currently needs. Tomatoes need N, Ca and K most heavily while developing fruit.
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Thanks for that. I was of the same mind with keeping N constant, but a recent conversation I had with a commercial grower, he said basically that you can’t have a good end product with high N and that it should be at least cut in half by week 6 from say 160 to 80 ppm. I figured he knows better than me lol.
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Let me know how it works and if you notice any difference. Is he saying week 6 for a typical 9 week commercial strain?
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He didn’t say directly but, I know most of the strains he runs do not go much past 60 days.
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Made a 0 N mix last night using Ca acetate as my sole Ca source. We’ll see how it goes.
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I found some information about N rates in flower:
Recent peer-reviewed studies have started to examine the response of Cannabis to mineral nutrients, but this area of research remains largely unexplored. These studies indicate the optimal N supply for both vegetative and flowering stages of cannabis production using conventional fertilizers is approximately 160 mg L-1 (Saloner and Bernstein, 2020, 2021). Plants supplied with N below 160 mg L-1 during the vegetative stage saw reduced photosynthetic capacity and plant growth, and during the flowering stage saw reduced inflorescence yield, though cannabinoid concentrations (not total production) were greater at extremely low N rates.
So it looks like there is a tradeoff. If you use very low N rates, it tends to concentrate cannabinoids more strongly at the cost of lower total bud and cannabinoid yield.
That makes some sense I think, because if you starve N, then the size of the buds is restricted, which increases your cannabinoid to plant matter concentrations. However, if you supply the optimal N for growth rates, it has an effect of spreading the cannabinoids over the larger bud surfaces.
Edit: Further discussed here:
Inflorescence from plants supplied with 160 mg L-1 N had approximately 30% and 20% lower concentrations of THCA and CBDA than plants supplied with 30 mg L-1 N (Saloner and Bernstein, 2021). But while nutrient stress and deficiency may enhance inflorescence cannabinoid content, this method is not ideal for optimizing overall plant productivity as plants supplied with 160 mg L-1 N yielded twice that of those supplied with 30 mg L-1 N.
So it seems you can boost concentration by 30% by limiting N, but you lose significant yield. If you’re producing for concentrates, it’s probably best not to drop N.
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What would you consider optimal N rates for veg and, flower? I usually start out around 150 ppm N. A friend on another forum runs 140 N all through veg up to week 7. Week 8 he drops it to 110 and keeps it there till plants are harvested. They have a perfect fade even with N being at 110. He is in perilite hempy buckets so, that might have something to do with it.
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