Calcium toxicity

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zem

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Too much calcium in tap water needs to be accounted for when calculating your fertiliser mix while using hard water especially in hydroponic systems. I have had this problem for a while now, it shows up on most grows no matter what i did or so I thought. It looked a lot like calcium deficiency and when i research calcium toxicity, i find no real info, it seems as if it is not that common a problem. Well, my source water is 0.48 ec and half of that is supposedly calcium, the other half mostly sulphates some magnesium and chloride etc..
I limited my usage of calcium nitrate to 1/4 strength and voila! I finally found the source of my problem.
Calcium nitrate is the most common fertiliser used in most commercial fertilisers and additives like calmag. So just a tip for hydroponic growers who use tap water or hard water, calculate the calcium in your fertiliser mix and add that to the calcium in your source water. Do the same with sulphates, make sure that the levels are acceptable, below 180ppm of calcium with 90 being sufficient. If you are having strange white spots or patches, with gold and brown spots that also resemble nothing but Calcium deficiency and you cannot find clear reasons, it can be that you have too much Calcium, excess calcium seems to be a problem that is very much overlooked. I had to crack this one all by myself with trial and error, and reading the same symptoms with others and cornering it. I hope that this might help some growers who are searching for calcium toxicity and excess symptoms and cannot find any good info, a problem that i had for a while,
Cheers! :D
 
Zem I believe you are onto something there. I think I have been recently having that very problem with my veg plants. Then I remembered that I had added calmag to my medium as a precharge. I cut back on the calmag and they are doing better.
 
Hey there HP :) how are you doing?
I have 240ppm water out of my tap, i assume there is around 120 Ca which is a lot of Ca but still not at a toxic level. when i go adding calcium nitrate at full strength, I am adding another 100ppm of Ca on top of that, and it is too hard to soften by topping since i am still topping with 120ppm Ca water.
 
Hey man, doing far better than the first half of this year.:) The bad thing with that situation of excess calcium is that it will build up on you over time unless your medium gets flushed well. (that is why I am such an advocate for top-feeding/hydro into coco coir, it flushes each time it feeds/waters)
You might be able to get away with just using some Epsom salt rather than calmag. The Epsom is all magnesium and another binder element.
 
i have both magnesium sulfate and magnesium nitrate. i guess that with the calcium nitrate dose goin way down, i need the extra nitrate so magnesium nitrate comes in, and knowing that i have significant sulfate level in my source water.
 
Plants are generally liking the new recipe. But the original problem remains, and i got what i think are very good pics to describe it. You can see its beginning and its progression to golden spots. It has baffled me, I was so sure it was calcium toxicity that i got over excited, since i cannot find anything else that is out of range in my recipe. what is more baffling, is that i tried a side by side test with GH ferts, and they did not cause this at all. not that they grew plants problem free, but this specific issue is non existent when i use them. This eliminates the possibility of a contaminant in source water. I am currently trying something else, I noticed that calcium in GH ferts is supplied through the addition of CaO and not CaNo3 and I know that there is a difference in the types of calcium and how easily the plants uptake them, so I went ahead, and added around 90ppm of CaO liquid form. It does resemble severe calcium deficiency, cutting down on calcium nitrate did not help in that particular issue.

View attachment 20161026_170403.jpg

View attachment 20161026_170504.jpg
 
That looks just like calcium deficiency. I doubt its bugs but it also looks like bug damage. Puzzling. Bwanabud had a similar issue with his grow. I think sometimes there are mediums and nutrient brands that just don't work well together, probably due to a chemical interaction between the 2 that locks up some of the elements. He had to change several things before he got straight.

I would try flushing them real good and then going back with nutes and small amount of calcium and see if that corrects it. It may take a while to see improvement though as that necrosis wont heal back, but hopefully it will stop it.
 
HP I found another possible culprit in my recipe, High K. in my research it turned out that high K Mg or N can lock up Ca and K is more often high. Well in my recipe, I had about 5-4-10 NPK the formulas suggested by GH are much more balanced N/K ratios like 1/1.3. Anyway, I am back to adding caclium Nitrate and lowered the PPM to 1040. this makes 6.5/10 N/K ratio + fresh Ca.
On the bright side, I am having great bud growth along with this calcium deficiency, and I did not mention to you the extent of what I am doing, I have 4 res's with 4 recipes, 1 GH, 1 classical hoagland base recipe, one high EC, and one "giving it my best" recipe, and that is the one with the most rust spots and the best bud growth. The one with the high EC is giving greener healthy plants, but smaller buds. The one with the classical hoagland base recipe, is giving medium sized buds bigger than that of higher EC, but I had to go out of the recipe just 20 days in when i began having more deficiencies. Finally the GH one is very green, was Mg deprived until i added extra, it has some great foolproof characteristics, that are great for vegging simply without having to do all the mixing, but compared to the level of control and bud size with DIY recipe, I am surely not going to switch to ready ferts for flowering. But having it as a control side by side is an amazing tool, to go more thoroughly into the research. The thing that I am trying to find out is how is it that I am not having any Ca deficiency with the GH formula even at much lower Ca in their recipe. I think that I nailed it now when I learned about the + ions in K and their ability to lock out Ca. I am optimistic again :)
 
Hey there HP :) :woohoo: I am happy here, plants are looking better, PH was set at 6 to encourage Ca uptake and today i can see obvious improvement. i am controlling the K deficiency in another res at 5.7 ph with ppm up to 1440 it seems k was absorbed fast but i am anticipating the Ca deficiency next but i am keeping space in my res for a sizeable topping with high Ca and up the ph a bit very soon.
the GH ferts res is surprisingly very stable, i can barely find any tiny spot, like fake plants, however, they are not very eager to flower if you know what i mean. I think the high ammonia and N to K is the reason behind all that, and the reason behind the lack of any calcium deficiencies. Giving plants high N makes great foliage but little bud as we all know. + the level of Mg deprivation prior to me supplementing it with epsom, was killer. that is the plants would have died, not a deficiency, but a deprivation, and only adding mg made them look like plastic plants
 
It is definitely all about the chemistry. That is why I prefer to use a nute brand that doesn't have pH buffer. I think they do better with a fluxuating pH than with a stable pH. The GH nutes are very similar to mine except the GH has pH buffers that will hold it very stable over time. But I can watch my pH drift from 6.0-6.1 down to 5.5 and if I allow it, it will drop all the way down to around 4.3, and I can see significant water taken out without a jump in ppm. I adjust it back up at that point after adding straight water top up. But I also have to use calmag additive up to about week 6-7 of flower.
 
I am puzzled again, as i was reviewing deficiency symptoms, i noticed that calcium deficiency normally shows on new growth first and this issue consistently starts on older growth first. The deficiencies that normally show on older growth are N,P,K,Mg, but it is only similar to Ca deficiency only on older leaves :huh: EC around 2.2, plants looking happy, but the spots, i would give anything to know what this is. I don't know how much this helps, BUT, this issue is VERY VERY strain dependent, that is it affects some strains way more than others which are barely showing very slight symptoms.
 
i also noticed that the rusting tends to develop towards the venial area rather than in between...???
 
it is not Calcium deficiency, it is more likely a PK thing, very thorough analysis had me conclude that this is mostly K deficiency boosted primarily by high calcium. The Ca content in GH is so low, and yet no Ca deficiency. I am back to thinking that this is the reason, too much calcium limiting K uptake at the time when plants need it most. I gave them a boost of PK raised the ppm to the 1220 mark, crossing my fingers and hoping.
 
So, further research and analysis done, I found what I believe is sodium toxicity, unless Mandala got it wrong, thids pic uploaded from their page on water http://www.mandalaseeds.com/Guides/Water-and-pH I have the exact same symptoms on one strain that is more fragile, and less pronounced on other sturdier strains. It begins from the veins rather than in between them. I analysed every chemical that i add and found the most probable culprits that are a low grade calcium nitrate and potassium nitrate that i had recently purchased. I went and got a good brand Yara Liva, changed my res, hoping to see that these spots are not spreading anymore.

View attachment sodium toxicity.jpg
 
In hydro, you shouldn't have sodium toxicity unless you are using something that is high in sodium and then not flushing your system periodically. If your source water is from a city/town, then it may be softened with salt at the treatment plant.
 
Reminds me of rust spots from salt on car bodies up north.
 
made a nice observation today, the rust veins seem to be healing, unlike the rust spots which are dead. with all 4 reservoirs and the research at its peak, i can say that i found out interesting facts, like the fact that my calcium ratio was high along with tap water. also found out that mj will produce at much higher EC during flowering than i once thought, i have the best results with ec of 1400 and more, i am trying ramping it up to 1650 in 1 res, will see how that does. And the GH ferts are giving me a good control res, where i can compare, and i can see that they use a lot more Ammonia and nitrogen altogether than recommended in fert mixes, but the high N seems to give the plants more ability to grow at lower EC, but also i can see that it promotes an elongated stretching period and more stretching altogether. I also have a 5th res for clones that are vegging, and the plants are loving that as well with a high ratio of ammonia/nitrate about 1/3 with no ill effects on the contrary, the "plastic plant" effect very prominent as i would like it in vegging :)
 
You keep experimenting on them, you will learn all sorts of interesting stuff about them. :)
 
I am sure by now that my diy recipe is growing more bud than gh flora is, although gh is growing plants that are looking very nice, i can notice with my eyes the difference in size of the buds.
 

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