Is this a magnesium deficiency ?

LED Grow update no.18, January 12th, 2011

Taken from "indoor growing", "testing the pro-grow 260 LED light"

Hey all,

So over the past 2 days I have noticed one of the plants showing a deficiency. To me it looks like a magnesium issue. I gave that plant an extra feeding of bat guano and some seaweed and tomato fertiliser. I mixed a heaped tea spoon of bat guano in warm/hot water and mixed it well. However, this extra feeding did not seem to fix the problem.

I did some reading on the subject and I cane to the conclusion that it might be that the magnesium is being locked out. Locked out meaning that the plant roots can no longer access the magnesium in the soil due to other issues. The water in my area is very hard and this can cause issues with magnesium uptake, over time. Possibly the hard water has affected the soil to cause this.

I went to the chemist and I bought some Epsom salts (magnesium sulphate) in an attempt to unlock the magnesium from the soil. I mixed one tea spoon with one gallon of water. I havenâ??t used all the water yet on this plant. I poured 1 litre of the Epsom salt water into the soil. You can see where I got this information on the home page of my grow journal blog. On the right hand side, where the links are, look for plants problems/disease. This is a very good link which shows many different plant problems and how to deal with them. LED Logger

So I hope this will resolve my magnesium issue. It seemed strange that this plant was the only one affected. But then I remembered that this plant has been watered much more than the others as it was positioned under the fan. This extra watering, with hard water, could have caused this reaction. I believe it is the calcium in the drinking water which affects the soil. I will keep you updated on the recovery of this plant.

It could be possible that I will have this issue with all the plants over the next few weeks. On my next grow I will have to get filtered water for the plants.

Enjoy the pics. If anyone has other ideas as to what has happened to this one plant I would like to hear it. I'm not a pro grower so advice would be great.

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Anyone got an answer for me ?

I would say NO, it is not. Here is a link, ( did not read it ) but the picture within has good examples of what i know to be magnesium def. Epsom Salts - UK420 ~~~~~~~~~~~~~~~~ I do not know what it is, Possibly scorching from spaying under high light/ temerature situations. Im sure someone here has had that exact problem. However, Your plants look fairly far along to me. Are they? dont forget that a good long leach is vital for nice clean smooth smoke, Organic ninjas please ingore this statement.

It is magnesium def. Also, that bottom photo looks too green, like there's too much nitrogen. Go easy on the ferts. The epsom salts will probably help make that yellow spotting go away, but just dumping ferts in is not a good solution. No offense, but it will cause more problems. Not sure of what ferts you have where you live, but a good way to grow is to use powder ferts that usually come in boxes, like in the states we have powder ferts by Foxfarm and Whitney Farms and Dr. Earth. You just put in about one half cup of fert per two gallons of potting soil and that should be all you need. Just use distilled water if you can.

high N bat shit can burn plants, it seems a low chance but it does happen. id say flush now and gear in for final flower. nutes are too much right now and may be built up in the medium. switch your plants around to get even rotations and flush accordingly. ph fluctuations could be a problem so lockout could be due to that as well. too much N can also be a factor.

yeah man i had same prob epsom salt done the trick but watch ur ph run off

thanks for the heads up guys. I added the salts and will continue with just water for now. There isnt much left in the bloom now. max 3 weeks or so.

Ill add a post regarding the final product.

Quote:

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Originally Posted by silent leprechaun

thanks for the heads up guys. I added the salts and will continue with just water for now. There isnt much left in the bloom now. max 3 weeks or so.

Ill add a post regarding the final product.

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foliar feeding is a great way to add utes without overdoing it. might be the way to go in your final weeks, but do flush first.

I'm sorry but I have to disagree with foliar feeding. I've seen alot of people do that in the past, but this kind of plant doesn't tolerate it well and usually what happens is killing the plant with ferts. I'd avoid foliar feeding if it were me. Just flush with plain water in the last two weeks before harvest.

I have just added some salts in a water feed. So far so good. Im only on watering now until the end of the grow. The plants are in week 8 by now. I heard that LED can add 2 weeks to a bloom. I dont know the logic behind that but it might be true. I should be harvesting by next week but maybe it could be 2 weeks due to the led making things take a bit longer. will be interesting to see. Ill keep an eye on the trichomes and Ill know.

I added another update to my grow journal (link in signature).
What do you guys think of the 190w LED and 80w CFL buds ? :)

Thanks for your help guys and gals