LED's cause bud to take in Mg and Ca differently???

[Oddjob]

Well I use RO water and never had any calcium/magnesium issues because I supplemented with 5ml of cal/mag per gallon of water. Since switching to LED, within the 4th week of flower I've been getting calcium deficiency. Would it be prudent to increase the calmag to 10ml per gallon?

 

[heckler73]

Well I use RO water and never had any calcium/magnesium issues because I supplemented with 5ml of cal/mag per gallon of water. Since switching to LED, within the 4th week of flower I've been getting calcium deficiency. Would it be prudent to increase the calmag to 10ml per gallon?

I think this is a good question. Ultimately, how much Mg can you add before toxicity is reached? And does that CalMag product also have Nitrogen?

 

[Oddjob]

I think this is a good question. Ultimately, how much Mg can you add before toxicity is reached? And does that CalMag product also have Nitrogen?

The brand is the popular General Hydro's CaliMagic which has an NPK of 1-0-0. I believe you're correct in what you are saying, to add more calmag when my plant is obviously calcium deficient would offset. Basically I added a tbsp of lime to each pot and hope this cures the ill. If anyone else has a better suggestion I'm all ears.

 

[gk skunky]

What's your pH running at. What grow method? If coco or soil if you aren't monitoring run off pH that's probably your issue. Doesn't matter if know what you put in if you don't know what remains in the media. If You dose too much Ca and you start interfering with other things like Fe, S, and Zn.

 

[Oddjob]

Running FFOF, always pH water and feed to 6.5 or damn near. Never have checked run off and never needed to...until now maybe? I've never had def issues, always have ppm and pH dialed in, so pretty sure this is an LED issue causing this.

 

[az2000]

The brand is the popular General Hydro's CaliMagic which has an NPK of 1-0-0. I believe you're correct in what you are saying, to add more calmag when my plant is obviously calcium deficient would offset. Basically I added a tbsp of lime to each pot and hope this cures the ill. If anyone else has a better suggestion I'm all ears.

Mic941 said General Organic's camg+ product has no N because it contains calcium carbonate, not calcium nitrate. Not sure how that affects its uptake/availability.

I agree with skunky that the first thing to check is your soil ph. If you don't have a soil ph meter, and have $50 to spare, order a Control Wizard Accurate 8. These things aren't hugely accurate. But, they can help confirm measurements of your runoff ph. Runoff ph isn't accurate either. It depends on how long you let water sit in the soil before displacing it as runoff. If you let it sit 30-60 minutes, the water will equalize to the soil's ph and the runoff ph will be very close to the soil's. But, if you water until runoff, you have to take the difference between input and runoff ph and subtract (or add) it to the runoff ph (because the water didn't have time to reach equilibrium). The probe helps detect (confirm) the time variable.

I think calmag is good in veg when using RO to replace the minerals lost from filtering. 2-3 ml/gal. But, in flower, if you get a calcium def, why not supplement with calcium? You can dissolve egg shell in vinegar, but it takes 2-3 weeks of dissolving. That won't help you now.

See, the following. They're about feeding Ca during transition of non-cannabis plants. But, that's one way to have some Ca on hand if you need it. You can also buy Ca. And, amend fine/powder dolomite to your soil

- http://forums2.gardenweb.com/forums/load/soil/msg0422555019136.html#GWCPostBody5
- http://gilcarandang.com/recipes/calphos/

 

[az2000]

Running FFOF, always pH water and feed to 6.5 or damn near. Never have checked run off and never needed to...until now maybe? I've never had def issues, always have ppm and pH dialed in, so pretty sure this is an LED issue causing this.

It could be you've had a soil ph problem but it wasn't enough to cause a serious deficiency. The LEDs pushing the plants in new ways could be the new variable, but the soil ph problem could what it's really revealing, that it's off enough to cause deficiency with this new demand.

Water your plant until nearly saturated (no runoff, but very wet), let sit 30-40 minutes, then water a little more until you get enough runoff to measure. The ph of that runoff should be very close to the soil runoff.

At least eliminate that variable. If you start adding stuff that's locked out, it won't help. You can foliar feed 5ml/gal calmag to keep the plant going until you're sure the soil isn't a problem. (But, if you're in a humid environment you need to keep bud rot in mind, use fans to dry the plant, or not foliar feed at all.).

 

[Oddjob]

Ok points well taken and will check run off and possibly try the GO camg+ to see if there is a difference in uptake potential.

 

[gk skunky]

Exactly and 6.5 is to high in my opinion. 6.3 is a magic number it seems but then again that was just my experience with that soil using both GH and FF nutes about 8 years ago. Lol 6.5 is already a little high to start with for Ca range. FFOF isn't the best buffering soil either I always had to add some domolite. Run off measurements like az pointed out should be taken with a grain of salt. But it's a good indicator if you are feeding too much,not enough to burn but enough to mess with other nutrients assimilations. Remember different elements affect pH differently. So while you May think you are feeding and adjusting pH right some salts can be accumulating over time and could present an issue like yours. Just one thing to check before just dumping more of something in there and potentially causing more issues inadvertently. LOL

 

[Oddjob]

6.5 is too high? let us re-examine the trusted nutrient chart, for soil that is:

 

[az2000]

Something else to consider is whether you let the soil dry enough between waterings. Soil ph rises as it dries. If you water too frequently you could be capping the ph range, contributing to acidic soil.

 

[FranJan]

Mic941 said General Organic's camg+ product has no N because it contains calcium carbonate, not calcium nitrate. Not sure how that affects its uptake/availability.

I've been meaning to point out that if you add calcium carbonate to lightly acidic water you get CO2. Why would anyone want CO2 in the root zone? I'm under the impression that would be a bad thing.

And food grade bone meal is a good source of calcium for plants IMO. It also contains a nice phosphorous boost, though I guess that may not be what you want all the time. Sprinkle on media, water in. If you want it to act fast you'll need to blend it with water though. And +1 to CalCarb which is a calcium/CO2 foliar that's great in veg.

 

[BDOGKush]

Well I use RO water and never had any calcium/magnesium issues because I supplemented with 5ml of cal/mag per gallon of water. Since switching to LED, within the 4th week of flower I've been getting calcium deficiency. Would it be prudent to increase the calmag to 10ml per gallon?

I'm using Area 51 lights, two weeks into flower and experiencing the same thing. My plant was showing slight signs if Cal deficiency, after watering with RO + calmag yesterday morning, the cal deficiency was way worse when I checked in on them yesterday night. Kind of bumming me out, buds are looking great and then a lot of my fan leaves went to shit in 15hrs.

 

[gk skunky]

6.5 is too high? let us re-examine the trusted nutrient chart, for soil that is:

That's actual soil pH not nutrient solution pH which are entirely different. You and are I were talking about your adjusted pH of your nutrient solution. As of now you have no clue where your soil pH is. Obviously not too bad but still unknown. 6.5 is perfect for soil 6.3 in my experience was perfect for watering the soil. That make more sense?


Just re read my other post. Sorry I meant to say 6.5 is high for the Fe range. Guess I fixated on the proposed Ca question. My apologies.

 

[BDOGKush]

I think I have a salt build up, I'm going to flush my soil and replenish with some 1/2 strength nutes.

 

[churchhaze]

Also, if you add it to water that is not acidic, you will raise the carbonate level. This can be beneficial as carbonate works as a pH buffer, and I see nothing wrong with using lime in soil.

Adding nitric acid to a solution high in carbonates and calcium will cause the CO2 to bubble out, leaving you with calcium nitrate in the solution. This is one way to get rid of excessive carbonates in tap water.

I've been meaning to point out that if you add calcium carbonate to lightly acidic water you get CO2. Why would anyone want CO2 in the root zone? I'm under the impression that would be a bad thing.

And food grade bone meal is a good source of calcium for plants IMO. It also contains a nice phosphorous boost, though I guess that may not be what you want all the time. Sprinkle on media, water in. If you want it to act fast you'll need to blend it with water though. And +1 to CalCarb which is a calcium/CO2 foliar that's great in veg.

 

[Oddjob]

I'm using Area 51 lights, two weeks into flower and experiencing the same thing. My plant was showing slight signs if Cal deficiency, after watering with RO + calmag yesterday morning, the cal deficiency was way worse when I checked in on them yesterday night. Kind of bumming me out, buds are looking great and then a lot of my fan leaves went to shit in 15hrs.

Bingo! That's what I'm talkin about, my ca deficiency onset was rapid as well. Pissed me the fuck off.

That's actual soil pH not nutrient solution pH which are entirely different. You and are I were talking about your adjusted pH of your nutrient solution. As of now you have no clue where your soil pH is. Obviously not too bad but still unknown. 6.5 is perfect for soil 6.3 in my experience was perfect for watering the soil. That make more sense?Just re read my other post. Sorry I meant to say 6.5 is high for the Fe range. Guess I fixated on the proposed Ca question. My apologies.

Ok gotcha now

I think I have a salt build up, I'm going to flush my soil and replenish with some 1/2 strength nutes.

I flushed as well and added a diluted nute strength....did nothing to solve the problem. I have never ever had a grow where my leaves have went to shit like this, not even when I was a noob. Luckily bud formation is still decent and things are sticky as hell under my apache at 600.

 

[gk skunky]

I would have flushed with 6.5 RO water 3x container size then fed full strength. I wouldn't have diluted the nutes. If it is deficiency or minor lockout causing the issue diluting the nute solution after flush is just prolonging the issue. Can't correct a def by removal via flush and then giving less of it upon replenishment. Once you can water again go back to full dosage and monitor soil and runoff too if you can do you can assess what all is going on in your root zone.

 

[BDOGKush]

I guess I'll give full strength nutes instead of half strength.

Flushing is going to be a chore with this SCRoG lol

 

[BDOGKush]

I would have flushed with 6.5 RO water 3x container size then fed full strength. I wouldn't have diluted the nutes. If it is deficiency or minor lockout causing the issue diluting the nute solution after flush is just prolonging the issue. Can't correct a def by removal via flush and then giving less of it upon replenishment. Once you can water again go back to full dosage and monitor soil and runoff too if you can do you can assess what all is going on in your root zone.

Hey Skunky, I'm not sure if I should flush or just give more calcium then what I was giving it. I fed with nutes at 6.4 PH, measured run off at 6.5 PH, seems like my soil is fine? I went through my notes and I had been giving the plant calmag in the plain water feedings but leaving it out of the nute feedings thinking the calcium in my nute line would be enough but maybe I should be giving calmag in every mix, nutes and water since I'm using RO. What do you think?