How much CALMAG you use?

Discussion in 'Coco Coir' started by masterlights, Sep 4, 2011.


  1. Like others have said, especially SCMC, it's due to the cation bank of coco. From my reading Potassium, Ca, and Mg are the preferred cations that are attracted to the negatively charged carbohydrate molecules that make up the cellulose in coco fibers. These elements are bonded to the coco and are released as needed when the roots uptake the elements. If you feed with too much Ca or Mg they will displace the K moecule and so the cation balance will be off, tipped in the direction of Ca or Mg at the cost of K. So when the plant needs K it won't be available. The key is once the cation requirements are met and the coco is buffered you need to feed while keeping the K, Ca, and Mg ratios in balance. Overfeeding with CalMag obviously won't accomplish that.
     
  2. Ok so I may have already asked this question somewhere else on grasscity... but

    Like you said you need to keep the K ca and Mg ratios in balance. Is there a good rule of thumb as to what those ratios are? I think they also change slightly through the different phases.

    SCMC, I'm pretty sure I asked you this before but I didn't quite understand the answer and I dont recall which thread that was in either.
    If we know the ratios we can calculate(assuming our bottles all have the Cal and mag levels provided in the garanteed analysis) exactly how much calcium and magnesium we need to be adding. I believe sulfur may also be to some extend involved in all this as well... is that true?
     
  3. This is a bit of a complex question and I have been working on it for some time.

    Roughly...

    During veg I like about a 1:1 of Calcium to Potassium and a 4:1 of Calcium to Magnesium.
    During bud I like about a 1:3 ratio of Calcium to Potassium and a 2:1 ratio of Calcium to Magnesium.

    These level are so approximate it is almost laughable... They slide all over the place in the feeding solution as the coco matures as well. I find that there are periods of growth, during the 3rd week of veg and the 4th week of flowering, where having a little extra Magnesium definitely helps.
     
  4. Thanks that answers it well enough. So far I've found just keeping an eye on the plants has been working well enough. I like to go a bit shy on the cal/mag as Id rather raise cal/mag then have pushed it too far and need to drop it back down.

    No calcium deficiencies yet but from what I can tell of magnesium deficiency is that if you catch it early enough its not going to kill your plant. My plants were growing vigourousy in the middle of mag def.

    So while you said it is very approxamate, with a bit of an eye for deficiencies it should be pretty close, and be adequate enough to keep the plants growing vigourously

    I'd rather ride on the edge of mag or cal deficiency than push too far and get K deficiency, does that sound like the way you would do it?
     
  5. I think that with close observation and a lookout for deficiency that any grower with a little knowledge should be able to work things out without too much of an issue with these.

    I find that Potassium and Magnesium deficiencies, at least in my own coco garden, are a lot more common than a Calcium deficiency. Actually, I think I have only had a Calcium deficiency one time in coco and it was a result of using Organicare's Calplex Calcium-Carbonate in combination with two other products, Huvega and Seaplex, that contained too much Sodium. It was very quick to resolve in coco.

    I have always be very conscious of the Calcium Cation Bank and have found that it is much more difficult to get the other cations to balance against the abundance of Calcium found in Coco specific nutrients. In most instances it is not Calcium we are short on in these nutrient mixes; more commonly the issues in coco are with Mag, Potassium, and Iron. Occasionally Calcium will even interfere with the uptake of Phosphorus due to precipitation which can be doubly detrimental. Imagine you're 3 weeks into flowering and the Cation Bank is overfull of Calcium. The deficiencies that appear are PK-Mag, the hat trick, and this will just destroy the harvest weight as the media is rebalanced and the excess calcium washed out while the proper level of nutrients are reintroduced.

    Cannabis is definitely a Potassium hog, and in flowering this will be the most prevalent element by at least 2x as much. I find that with the switch to flowering nutrients with higher ratios Potassium, after a good long vegetative period where the coco was highly enriched with Calcium, that the balance of Magnesium (the least prevalent of the top 5 elements) against these two other cations is absolutely critical to maintaining that vigor through flowering.

    We start by trying to dial in the Calcium level just right. Acknowledge that the coco is retaining this cation and maturing over time. Also understanding that as the coco decomposes it is naturally releasing some Potassium. Adjust our nutrient solution for the maturity of the coco and the period of growth to accommodate changing nutritional requirements, namely by increasing the amount of the least copious element of the "Top 5" Magnesium. When you do it properly the yields are absolutely mind blowing.

    And honestly, it sounds a lot harder than it is. Just one of those things you have to be present for, see the bad things happen a few times, and have a good feel for when to change what based on experience. For me I try to just keep my runoff volume nice and high, my runoff EC close to my solution EC, and this lets me know that the plants are consuming the nutrient solution I provided today rather than weeks of "leftovers." Without keeping the media rinsed and balanced mixing up a proper nutrient solution is a complete shot in the dark. Sometimes you'll hit it, sometimes you won't, and a lot of growers mistake luck with skill.
     
  6. #46 Thedillest, Feb 27, 2012
    Last edited by a moderator: Feb 27, 2012
    Thanks SCMC, I'm feeling pretty confident now after reading that.

    I should be pretty set for a successfull grow by the sounds of it. I vegged with H&G cocos A+B. the H&Gcocos has copious amounts of calcium in it, plus I'm using tap water. I figured it would be a good idea to use something a bit more bloom specific during 12/12 because H&G is designed for both veg and bloom so i figure they must make a bit of a compromise to do that. What I've got is Tiger Bloom and Big Bloom. I'm going to innoculate my coco with the Mycrorhyzal and Bacilius products from GH, using airstones/water heater/carboload(AN), and the Big Bloom from Fox farms. Then what I want to do to give my H&G cocos AB a bit of an extra kick is mix in equal parts of the H&G AB(NPK 5.5-3.4-9.1) with FF Tiger Bloom(NPK 2-8-4). That'll bring all the numbers in a more bloom appropriate range(NPK 7.5-11.4-13.1).

    I won't be using any of the fancy bloom enhancers or additives like shooting powder or top booster or bud xl and algen extract that H&G makes, instead I'll just run my Tiger Bloom and HG combo, with innoculated coco and add in a bit of carboload(cant get any unsulfered molasses around here), through flower and I'll be very minimal on additives(only adding extra fulvics and humics in small amounts).

    so the Tiger bloom I don't imagine has anywhere near the Calcium as the HG, which is great as it doenst start be used until the plants are into 12/12 and the H&G still adds in a good amount of calcium. There will also be plenty of P and K. The only thing I should need to adjust throughout the next 10 weeks will be the level of magnesium, and I'll use epsom salts for that, as needed.

    I'm now 2 and a half weeks into 12/12 so it's good to finally feel like I have my nutrients sorted. This is my first grow, so I've been relying on luck thus far quite a lot, but trying to a put a bit more skill into now that I'm 12 weeks into my grow(vegged 9 1/2 weeks).

    Hopefully it all works and is as simple as I'm hoping. I'll let you know how my recipe turns out

    I was going to upload a picture, but my pictures are too big to be uploaded... so unless I can figure out a way to shring them?
     
  7. Try GIMP or Fspot, or picasa. They are all free.
     
  8. I use the whole canna line with RO water and then add CalMag, Bioweed, and superthrive. I use 5ml per gallon of calmag, always have.
     
  9. @SCMC -- Thanks for all the good info on coco's cation banks, that shit was all a blur to me before but I think I understand it a little better now. I'm currently using 7gs Maxibloom with 5 ml CalMag per gal, however I'm interested in using a two separate supplements for the calcium and magnesium instead of the combo. What would you recommend? Epsom Salt and Dolomite Lime?
     
  10. There aren't a lot of options for separate Calcium and Magnesium supplements. Humboldt Nutrients has SeaCal and SeaMag I think. Organicare has Calplex and Huvega/Humega, and Cutting Edge Solutions has Plant Amp and Mag Amped.

    Out of them all the one I had the best experience with was the CES Plant Amp and Mag Amped. Their Micro supplement is the tits also.

    These days I find that it's really more Magnesium that my coco system craves. Even with my Calcium supplement carrying some Magnesium, it never seems to be enough, so all I do is add Epsom Salt on top of that and that has given me plenty of control over the levels of these cations.
     
  11. consider that it's not a matter of whether you have enough magnesium as whether its the right type. not all magnesium is the same. for example uptake will vary between magnesium sulfate and sulfate of potash magnesia. I know you're probably thinking, I have potassium covered so why would I add this. I do not have the exact sceince on hand. However amending with sulfate of potash magnesia (%50 magnesium) at the low low rate of 1/4-1/8 cup per CF will solve for magnesium.... it is strong stuff and only amended when magnesium is seriously deficient. adding compost or a chelating agent like kelp meal will transport it to your plant in which case even less is added.
     
  12. Su-Po-Mag is 50% Potassium...
    Only 11% Magnesium.
    And still all the sufate that comes in Epsom Salt.

    With Epsom Salt at 9.8% magnesium... I don't see the need to spend all that extra money.

    Where and how the Epsom Salts are made is important. Certainly. And if we really want to pull hairs about availability of elements then we should be talking about low molecular weight magnesium (like in Cutting Edge Solutions Mag Amped).

    Using an incredibly powerful fertilizer, rich in a competing cation, to an already imbalanced media is a bad idea from every angle. Slow and steady wins the race. Just 10ppm of Magnesium to your solution could be all that is required. Often this is a 25% or greater increase of that particular element.

    I appreciate the heads up about the Su-Po-Mag but with coco, and particularly unamended/hydroponic coco, Epsom Salt works very well. And if it ain't broken...
     
  13. [quote name='"SCMC"']Su-Po-Mag is 50% Potassium...
    Only 11% Magnesium.
    And still all the sufate that comes in Epsom Salt.

    With Epsom Salt at 9.8% magnesium... I don't see the need to spend all that extra money.

    Where and how the Epsom Salts are made is important. Certainly. And if we really want to pull hairs about availability of elements then we should be talking about low molecular weight magnesium (like in Cutting Edge Solutions Mag Amped).

    Using an incredibly powerful fertilizer, rich in a competing cation, to an already imbalanced media is a bad idea from every angle. Slow and steady wins the race. Just 10ppm of Magnesium to your solution could be all that is required. Often this is a 25% or greater increase of that particular element.

    I appreciate the heads up about the Su-Po-Mag but with coco, and particularly unamended/hydroponic coco, Epsom Salt works very well. And if it ain't broken...[/quote]

    Thanks again.. Do you think i should add extra magnesium on top of the 5mls of CalMag that i use? Other than CalMag i just use 7gs maxibloom . I read earlier that you add a little extra magnesium during 3rd week veg and 4th week flower, is that really specific to your system or could that work for me as well? Should i cut back on the CalMag at some point and add extra magnesium? My past two grows (2 plants each) have yielded nicely however i feel like they really slowed down at the end of flower. Could this possibly be because i never cut back on my CalMag and overloaded the cation bank with calcium? Thanks again and please don't take too much time answering my questions if they are confusing.. i know i have a lot of reading to do on this topic .
     
  14. I cannot know because I am not in your grow room growing your plants.

    5ml of Cal-Mag Plus gets you at least 20ppm of Magnesium. I'm not sure how much Magnesium is in MaxiBloom, or how much MaxiBloom you are using, but as long as you're picking up another 30 or 40ppm from that then you should have enough Magnesium. I suggest reacting appropriately to nutrient deficiency but don't try to add more magnesium if your plants haven't "asked" for it before or now.

    Decreased yields are a side-effect of excessive amounts of Calcium but this may not, and is likely not, the only factor in a diminished harvest. Any stress from nutritional imbalance, poor environment, or physical damage at the wrong point of life is going to reduce the harvest. Work on dialing in the other aspects of your grow before changing your nutrient lineup if your plants are looking healthy otherwise.

    If the plants are suffering from leaf necrosis, specifically interveinal chlorisis, then more magnesium is going to be a good idea. If you are getting the interveinal chlorisis plus the leaf margins (edges) are curling upwards and cooking also, then the remedy is probably less Calcium and perhaps slightly greater levels of Potassium and Magnesium.

    Baby steps. Small changes. Good record keeping. That's how to improve the most from grow to grow.
     
  15. I've been trolling the forums gaining knowledge anonymously, but this quote made me register if only to compliment this exceeding correct statement! I too, have been guilty of this misconception!

    Many thanks for the very percipient observations and explanations. I have recently begun using COCO in a recirculating hydro system. Everything has been fine except the struggle to keep the ph up. This has given me food for thought.
     
  16. I also am using AN in my first coco/perlite grow. How much sensi a/b do you start seedlings on? Anything else in the first two or three weeks? Is 1/4 or 1/2 strength recommended? (growing autoflowers) Thanks in advance for your help. peace...bongwater
     
  17. Anybody home? Was it something I said? peace...bongwater
     
  18. Nah man, you're just quoting year-old posts. It happens.
     
  19. Ill have to read through this whole thread when Im not feeling dazed from this Larry OG!

    But for now heres my input...when I was using Distilled water I was using 1 tsp/gal but now that I have switched to tap I cut back to 1/2tsp/gal. Ill update if I see any problems
     
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