My plaants recently fell very ill after a major cal deficiency due to using RO and not using calmag (stupid, i know. Didnt know i had to add micronutrients to RO) i sprayed my plants with half dose calmagic by GH, AND started watering with gallons with added half dose calmag. My plants are all flowering. Fast n vast, sour d , critical jack, and og kush. All autoflowers. The sour d is ahead by one week and took the most beating from the cal deficiency. In the past few days though i noticed some darkening leaves on my fast n vast, ill include pictures but its showing greyish blueish spots on their top leaves and its starting to scare me. My plants are already damaged and i really dont want them to get worse and die... am i using enough calmag? And am i showing the beginning of a different deficiency? Please help! They are all at about 40 days from seed. Under 2 amare solarpro 300s, temps constant 75-80 and humidity never really above or under 50% at this point. No extra nutes added yet, in fox farms ocean forest soil.
Cal mag deficiency, and something else?? Help
- Thread starter Randomusername123
- Start date
Renaissance Redneck
A Lovable Little Fuzzball
- Joined
- Dec 16, 2012
- Messages
- 9,540
- Reputation
- 0
- Reaction score
- 23,213
- Points
- 0
- Currently Smoking
- You Bet
Yikes. It looks like you have a lot going on there, Random.
By day 40, even with FFOF, I would think you're way behind in feeding. You have too much def to even talk about. Also, Fox soil is still dealing with a bad rep for crappy pH buffering.
I think you can still pull a harvest out of this, but definitely reduced.
What nutes do you have on hand?
Do you have a way to check pH?
And when you say you were watering with "gallons" , are you saying that you were flushing?
Last question for now, how close are your lights? Some of the worst damage looks a lot like bleaching to me.
By day 40, even with FFOF, I would think you're way behind in feeding. You have too much def to even talk about. Also, Fox soil is still dealing with a bad rep for crappy pH buffering.
I think you can still pull a harvest out of this, but definitely reduced.
What nutes do you have on hand?
Do you have a way to check pH?
And when you say you were watering with "gallons" , are you saying that you were flushing?
Last question for now, how close are your lights? Some of the worst damage looks a lot like bleaching to me.
How close do you have those LED's? I have seen similar symptoms when I had plants outgrow my tent height. You could easily see the differance between the buds directly under the light and the buds outside the edges of the lights. The ones under the LED ,only about 6-8 inches, fried very similar to what I see in yours. You may try to raise the light a little and see if that helps.
Do you have a way to check the pH of your medium. I suspect you may be into lockout some. With the mix of symptoms you've got, establising an accurate medium pH is key to determining any diagnosis and treatment. An Accurate 8 soil pH meter is a well known and highly recommended pH soil probe. If you can not get access to a quality pH probe, here is a thread that gives an alternate method that is highly variable and basicly a last resort and better than nothing: https://www.autoflower.org/threads/...-for-run-off-testing-and-ph-estimation.41733/
I grow under LED and use RO water both. I start adding GH CaliMagic at 1 ml/L from day 1 and bump up to 2-3 ml/L during flowering. At first sign of any def, I up another 1/2 ml/L until under control.
Do you have a way to check the pH of your medium. I suspect you may be into lockout some. With the mix of symptoms you've got, establising an accurate medium pH is key to determining any diagnosis and treatment. An Accurate 8 soil pH meter is a well known and highly recommended pH soil probe. If you can not get access to a quality pH probe, here is a thread that gives an alternate method that is highly variable and basicly a last resort and better than nothing: https://www.autoflower.org/threads/...-for-run-off-testing-and-ph-estimation.41733/
I grow under LED and use RO water both. I start adding GH CaliMagic at 1 ml/L from day 1 and bump up to 2-3 ml/L during flowering. At first sign of any def, I up another 1/2 ml/L until under control.
How many days has it been since you started spraying? Calcium moves very slowly so the recovery will take awhile. Even regular litmus paper will let you test the run-off. This looks like you may have salt deposits from the nutes that the plants already used and more than likely caused your pH to go up too high, resulting in soil salinity and nute lock-out. Salt deposits can cause harm to plants by competing for the available moisture and causing desiccation or "burning"of tissues. In addition, these deposits can affect the pH of the growing media as well as block absorption of essential plant nutrients. FoxFarm is known to have salt buildup from their hot soil in the latter part the grow as the plants use up the nutes.
Try flushing 2x the soil volume with tap water is fine as long as it's not too hard and then finish off with something like AN's final phase, which is exactly what it's for or any other brand's similar media flush. Check your pH and then feed at 1/3 dose of nutes and foliar spray calmag at half strength and nutes at 1/4 for quicker absorption. You can increase the dose once they recover.
Raise the lights to 24" and turn off the surrounding COBs to reduce the intensity since they are deficient now and do not have the nute requirement to deal with the intensity like calcium, magnesium and potassium. You can turn them back on once they recover. HTH.
Try flushing 2x the soil volume with tap water is fine as long as it's not too hard and then finish off with something like AN's final phase, which is exactly what it's for or any other brand's similar media flush. Check your pH and then feed at 1/3 dose of nutes and foliar spray calmag at half strength and nutes at 1/4 for quicker absorption. You can increase the dose once they recover.
Raise the lights to 24" and turn off the surrounding COBs to reduce the intensity since they are deficient now and do not have the nute requirement to deal with the intensity like calcium, magnesium and potassium. You can turn them back on once they recover. HTH.
Last edited:
My lights are always about 20in away from the top of my plants, these autos wont stop growing despite damage though and ive put my lights as high as i can in my tent at this point, when i said gallons i only meant that i used half dose cal mag in a gallon as it calls for a full teaspoon per gallon. I think my biggest mistake was i never used calmag until about a week ago and for a few weeks it showed signs of cal deficiency and i didnt do anything about it out of fear of hurting my plants more than they already were, the other 3 seemed to get better with the use of the calmag but my fast n vast seems to be a bit finnicky, ive moved her out from under direct light to see if she calms down, im still watering with calmag, my water is phed at 6.5 , i havent tested run off yet though, ive only flushed one of my plants once before and the run off was reading 6.0. I did use big grow at one point during my grow as well a few weeks back, but stopped because my plants showed brown spots and yellowing immediately after.. i assumed it was because of the calcium deficiency? ... not sure what to do i fear this poor baby will die
I started the sprays about 6 days ago, but layed off because my fast and fast began worsening. I stopped the sprays but have added half dose calmag to the water i feed each of my plants, i have been scared to use more or keep spraying because of possibly hurting my plants with the nitrogen added in the calmagic, at the point now to where im scared to do anything that could possibly make things worse but i begin to wonder if maybe im just not using enough calmag or it simply hasnt been long enough to see improvement from her.
If you run off pH is 6. It's a little low for soil and can also cause lock-out. It should be around~6.5-6.7 for soil. The spray is much quicker since calcium moves very slow. It will take awhile due to the extent of your deficiency.
Last edited:
Similar threads
