Any recommendations on how to salvage these ladies? I feel like they've not been growing much and their neighbor seems to be putting on more weight. Should I stop the autopot using the reservoir on the sick one and hand water to it for a week with just Canna A+B and CalMag (putting in the tray not top watering)? I'm out of town next week so not sure what I can do at this point. I was expecting it to fatten up a little bit more.
Lockout? Cal-Mag Deficiency? How to diagnose and deal with?
- Thread starter zipperdoyle
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If I was you, I'd find someone to run a test on my nutrient solution and see whats going on, see if excess phosphorus is accumulating in your res. She will finish fine but you are gonna lose some yield. You say the other plants are doing okay, are they using the same res and coco?
I never had much luck bringing them "back" after they were that far gone. The end product was always fine though. A good flush and fresh nutes never hurts, so you can try that. Those buds look really beautiful!
Yep I'm using the same res with the other one, which is about a week behind or so in the flower cycle but it's fattening up. Like you said I can't do too much at this point and just let her grow. I'm just trying to figure out how to prevent in the future. Can't tell if I didn't provide enough P when it started flowering and it locked itself out of Cal or Mag. I'm doing two plants in this tent so maybe I'll do a separate res so I can manage when one flowers earlier/later and troubleshoot.
The flowers look nice they are just a bit on the small side for my liking.
I don't want to bore you with the explanation of cation exchange in Coco, unless you want me to. However, you sometimes get to a point where the coco itself is so "starved" for calcium and magnesium that it absorbs all of it out of the nutrient solution, and releases all it's potassium. Thinking you need to "increase" the calmag addition, you bump it up a little in your regime. Which, only exacerbates the issue because the coco just takes all that up too and releases even more potassium further increasing the potassium toxicity. Then, if you do get enough calcium into your solution, you have a potassium toxicity, which locks out calcium. See the compounding issue here?
If, you think this is the case in a grow and you catch it early, you can in theory buffer the coco mid grow by a thorough flush with calmag water. The goal here would be to not only provide the medium with enough calmag, but wash out the potassium that it is releasing. I'd say you would then need to apply the correct nutrient solution and get things back to normal asap.
In my system, I always buffer my own coco. Hydrate, rinse, buffer in a 1500+PPM solution of calmag, and rinse. Then in my nutrient solution I feed extra calmag for my coco, not for my plants. I always try to think of it like that, I have to feed my plants calcium and my coco calcium. My base nutes have plenty of calmag for the plants, but not enough for the plants and coco as it breaks down. For me, that's an additional .5ml calmag per gallon of nutrient solution.
I know you are using AutoPots, so you will have to apply this information to your specific system. The principals however are the same.
I've read numerous articles and have a pretty thick notebook about growing in Coco. This is a copy paste from a website that explains maybe a little better than I can. https://www.shogunfertilisers.com/e...hen-growing-in-coco-coir-and-their-solutions/
Potassium toxicity & cal-mag deficiency
As Coco has a high cation exchange capacity, when you feed your plant with calcium or magnesium, the minerals may never be available to your plant, as it will be exchanging it’s self for sodium and potassium. As explained in the washing versus buffering blog article, coco coir substrates prefer to bind to magnesium and calcium compared to sodium and potassium. This means that your plant, when given a normal dose of Calmag, will actually have sodium and potassium available to uptake as opposed to the desired Cal-mag combination.
By buffering the coco completely until saturation, you can guarantee any further CalMag that that is fed into the media will not be absorbed by the saturated substrates but will sit in-between the spaces of the media ready for uptake by your crops. Remember when you buffer the media with a calmag solution you have to wash the sodium and potassium out of the media other wise you will get toxicity. If you are half way through your grow and did not take this precautions, taking a calmag and foliar spraying it on your crop leaves can be a more efficient way to directly remedy the problem. Make sure you do this at low light levels or this can results in burning of the leaves. The addition of a wetting agents will aid with the uptake of calcium via the leaves. In addition foliating calcium is a great Idea as it is quite an immobile mineral, which means it has a lot of trouble moving from one are to another regardless of media.
You see although you have remedied the calcium nutrient lock out problem, you start an over supply of potassium problem. There are 2 things you can do to handle this, the first would be for you to wash out your media again after buffering. The second is to use PK warrior for only one week in week 3 (Day 21) of the flowering cycle (short days). Although it makes the process longer we always suggest to wash it out once again, so that you can start your grow on a canvas where you don’t have to modify measurements as much.
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Even tho I dont run hydro or coco, i definitely agree with american hillbilly on this. Excess nutes in soil can cause problems too. I had magnesium lock out from overloading on potassium on my last run. Was so bad I couldnt get rid of it. But it grew just fine. I think yours will be ok too. Mine flowered out and stuff just fine, I cant say anything on potency or anything as it was a photo and I hermied by leaving my room lights on all night.
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Top water, feed to a good runoff bout a quart os so once a week will help. Remove them from the autopot trays first..In a utopots nutrient salts build up in the coco.. check runoff ec, you'll see.. and what american hillbilly said...
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