Limestone rock for calcium deficiency?

zac graves

Member
so I've had mild signs of calcium deficiency and don't have the $$ for cal.mag. So I used some fresh limestone rock that was dug up from my back yard and crushed it with a hammer, thus making powder. So I sprinkled a good tsp into each 3 gallon and watered afterwards. My neighbor is the one who recommended it. I'm just wondering if it's legit and will help my gals IMG_4890.JPG
 

Richard Drysift

Well-Known Member
It has to break down first in order to become available to the plants. They cannot absorb whole limestone rocks. That's why people use soluble a cal mag. Epsom salts may help if you hydrate it but nothing works as fast as liquid calmag. Don't worry though it doesn't look like a serious deficiency; save up some dough & get calmag when you can. Looks more like minor leaf damage; a calmag def usually looks sorta like rust spots.
 

zac graves

Member
It has to break down first in order to become available to the plants. They cannot absorb whole limestone rocks. That's why people use soluble a cal mag. Epsom salts may help if you hydrate it but nothing works as fast as liquid calmag. Don't worry though it doesn't look like a serious deficiency; save up some dough & get calmag when you can. Looks more like minor leaf damage; a calmag def usually looks sorta like rust spots.
I trimmed all the leaves with rust spots. Eventually it'll do that. And yea I need to get calmag for sure. But it wasn't whole rock. It was like powder after I smashed it
 

zac graves

Member
It has to break down first in order to become available to the plants. They cannot absorb whole limestone rocks. That's why people use soluble a cal mag. Epsom salts may help if you hydrate it but nothing works as fast as liquid calmag. Don't worry though it doesn't look like a serious deficiency; save up some dough & get calmag when you can. Looks more like minor leaf damage; a calmag def usually looks sorta like rust spots.
I get what you mean by not being able to soak it up, but because it was like powder, when I watered it, the water turned white so it looked pretty solid. I'm hoping
 

Richard Drysift

Well-Known Member
Trimming off the affected leaf will not solve the problem if in fact you do have a calcium deficiency which doesn't even look that bad to me; a pic of the whole plant might help. One leaf only tells so much.
Even if you pulverized the limestone to a fine dust it still needs to be broken down by soil microbes before it can be absorbed by the mycorrhizae fungi attached to your plants root system and then converted to usable sugars through photosynthesis. It will take awhile (think weeks or even months) before whatever calcium contained in the crushed rock you added can be absorbed and used by the plant so it will not help for several weeks or possibly even months. Or you could just give soluble liquid nutrient that is immediately usable by the roots directly.
This is the difference between growing organic and growing with nutrients. Adding dry amendments like crushed stone, minerals, and/or kelp meals, etc to the soil needs time to "cook" in during which time the ph typically drops..."hot" soil. It takes about a month for freshly amended soil to normalize ph by itself.
I know that if you need some fast calcium in a pinch you can use hydrated Epsom salt at about 1 tsp per gal of water. It's cheap and easily found in any health store. Bubble it for an hour+ w/ an airstone to mix it which should help a calcium deficiency if that's what you have. Hydrated D-lime could work also but I warn against using crushed rock from your backyard unless you know for sure the mineral content. Dolomite lime and/or garden gypsum are good sources of cal & mag but you need to add it into the soil way before you put the plants.
 

zac graves

Member
Trimming off the affected leaf will not solve the problem if in fact you do have a calcium deficiency which doesn't even look that bad to me; a pic of the whole plant might help. One leaf only tells so much.
Even if you pulverized the limestone to a fine dust it still needs to be broken down by soil microbes before it can be absorbed by the mycorrhizae fungi attached to your plants root system and then converted to usable sugars through photosynthesis. It will take awhile (think weeks or even months) before whatever calcium contained in the crushed rock you added can be absorbed and used by the plant so it will not help for several weeks or possibly even months. Or you could just give soluble liquid nutrient that is immediately usable by the roots directly.
This is the difference between growing organic and growing with nutrients. Adding dry amendments like crushed stone, minerals, and/or kelp meals, etc to the soil needs time to "cook" in during which time the ph typically drops..."hot" soil. It takes about a month for freshly amended soil to normalize ph by itself.
I know that if you need some fast calcium in a pinch you can use hydrated Epsom salt at about 1 tsp per gal of water. It's cheap and easily found in any health store. Bubble it for an hour+ w/ an airstone to mix it which should help a calcium deficiency if that's what you have. Hydrated D-lime could work also but I warn against using crushed rock from your backyard unless you know for sure the mineral content. Dolomite lime and/or garden gypsum are good sources of cal & mag but you need to add it into the soil way before you put the plants.
Thanks for all that . Yea I think my best bet is getting the cal mag plus because in a week or two I'll be ready for flowering. Being that it's my first grow, I'm not looking for tall plants. Like a foot and a half by harvest. Would it be safe to flower with this problem or should I solve it completely before? I switch to 12/12

And I have a mix of 5000k and 6500k cfls, if it looks yellow in some spots. I'll be flowering with a 400w hps light. I'm doing LST as well. Picture number one is the right, pic 2 middle, 3rd is the left, 4th whole view.IMG_4895.JPG IMG_4897.JPGIMG_4899.JPG IMG_4903.JPG
 

Richard Drysift

Well-Known Member
Your plants are gorgeous. There's no calcium deficiency. You really only need to add cal-mag if your plants do not get it by their water source. Usually peeps who use RO or distilled water need to add it back in. I would get it if you use stripped down water otherwise just keep doing what you are doing; your plants look good flip em when you want to.
Only thing I would suggest is to veg under the 400w for awhile if you can. Plants under cfls tend to have lengthy spaces in between the nodes which makes them stretchier later on. Hid lights give nice tight internodes which allows for bigger buds overall.
 

zac graves

Member
Your plants are gorgeous. There's no calcium deficiency. You really only need to add cal-mag if your plants do not get it by their water source. Usually peeps who use RO or distilled water need to add it back in. I would get it if you use stripped down water otherwise just keep doing what you are doing; your plants look good flip em when you want to.
Only thing I would suggest is to veg under the 400w for awhile if you can. Plants under cfls tend to have lengthy spaces in between the nodes which makes them stretchier later on. Hid lights give nice tight internodes which allows for bigger buds overall.
So I would introduce the hps at 18/6 and slowly decrease it? And is it okay for me to start flowering eventually with this Deficiency?
 

Richard Drysift

Well-Known Member
What deficiency? Your plants are green and healthy... you don't have a calcium deficiency. That lil blemish on the leaf is no biggie. Sure 18/6 for veg cycle is good; you can slowly decrease if you want or go right to 12/12 when you wanna flip em its up to you.
 

zac graves

Member
What deficiency? Your plants are green and healthy... you don't have a calcium deficiency. That lil blemish on the leaf is no biggie. Sure 18/6 for veg cycle is good; you can slowly decrease if you want or go right to 12/12 when you wanna flip em its up to you.
I mean eventually it'll spread. I'm probably just paranoid cause they're like my kids lol. But thanks for everything fr. I feel a lot better
 

Richard Drysift

Well-Known Member
They are talking to you it's just you need exp to hear what they are saying. That necrosis at the tips usually indicates that you are giving them a bit too much N. It also possible it could just be from letting the soil get too dry. I say it looks like a burn only because the plants are such a deep green color; they certainly are not starving and it's very easy to give too much nutrient just by following a feed chart. Either way water them as normal without feeding for a week; if it is N burn it is relatively minor. Resume feeding at a lower strength until they get bigger. They need very little nutrients at this point; they will need more when they start growing flowers. A ppm pen is more accurate when mixing nutrients than using a tsp. When you say barely give them nutes how much do you give them and what do you give?

You want to look at all your plants now; different strains can have slightly different needs. Adding limestone could push your ph down a bit more acidic than your plant may like so that's one reason I wanted to chime in when I first saw this thread. Lime can be used to adjust soil ph down; you would need to add a whole lot of lime though in order to move the needle.
 

zac graves

Member
They are talking to you it's just you need exp to hear what they are saying. That necrosis at the tips usually indicates that you are giving them a bit too much N. It also possible it could just be from letting the soil get too dry. I say it looks like a burn only because the plants are such a deep green color; they certainly are not starving and it's very easy to give too much nutrient just by following a feed chart. Either way water them as normal without feeding for a week; if it is N burn it is relatively minor. Resume feeding at a lower strength until they get bigger. They need very little nutrients at this point; they will need more when they start growing flowers. A ppm pen is more accurate when mixing nutrients than using a tsp. When you say barely give them nutes how much do you give them and what do you give?

You want to look at all your plants now; different strains can have slightly different needs. Adding limestone could push your ph down a bit more acidic than your plant may like so that's one reason I wanted to chime in when I first saw this thread. Lime can be used to adjust soil ph down; you would need to add a whole lot of lime though in order to move the needle.
Yea I thought it was one thing but may be nute burn instead. I've kinda been reading my calendar wrong for whatever reason. I'm always high when I look at it so my counting was off. I'm on 2 and 3/4 weeks into veg and fed it like it was the third week. This Friday is the 3rd week. I use fox farm trio so I fed them a lil too early. I fed 3rd week at half strength which would've been 2nd week full strength. Whoops :eyesmoke:
 
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