Cal Mag Problems from Garden Lime (I think)

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Gurtgurt

Gurtgurt

128
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Hello friends. My plants are strain LSD. They are now in about week 12 since sprout and week 1 of flower. The yellowing and drying old growth, and yellow new leaf tips, have been a chronic problem. (I added dolomite garden lime, and not dolomitic lime to the soil, See here)

I water when the leaves droop which has only been about once a up until now. Going forward probably every 4 days. Each time I water a plant gets 1.5 gal, in 5 gal pot (soil). pH I estimate at 6.1 - 6.4 (varies).

A user suggested epsom salt and miracle gro fertilizer for acid loving plant. I only used them once at low concentration.

I use the fox farm trio for nutrients. To one gallon of water I add:
Big Bloom worm castings almost 3 tsp always,
Grow big veg fertilizer, 1 tsp tapering off,
Tiger blüm flowering fertilizer, 1/2 tsp first time last watering (tapering up).
Incredible, right? Sometimes I'll throw some Epson (R) salt crystals in there, but I'm a-scared to go overboard. I'll probably water tomorrow morning!

I suspect I have calcium or magnesium psychosis from the lime I added early on. The leaf stems have been purple for a while, I thought that was from LED lights. Now, in the pictures, I can see some of the main stems are getting red stripes.

Any suggestions on hOw2FiX? I pH with drops, I stand up to pee, and I don't have an EC meter. The plants get tap water. I am authorized to distribute up to $250 in my own personal scrip for the best suggestion. Thank you.
 
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Mugwort

Mugwort

389
63
Do you use tap water, r/o water? You have some kind of mineral deficiency/toxicity going on. If you’re going to grow you should invest in a pH/TDS meter so if the time ever occurs that you need to check runoff pH or tds you’ll have one. Could use one right now!
 
Aqua Man

Aqua Man

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Stop under watering, get a soil meter and make sure you push it to the bottom..

As @GNick55 said raise the light up. What make and models is it and how far above the plants? I take these are photos and been on 12/12 for a week?

Get the pots up off the floor a cold root zone may be partially contributing to a uptake issue as is the light intensity which I'm pretty sure has been an issue for some time now and has stunted them.

How low are the night temps dropping?

Imo ditch the tiger bloom all together.

If ya choose the post I don't want a penny so if your inclined you can contact @logic and donate it to the farm or possibly the photo of the month contest as we have a load of great and deserving ppl here.
 
Aqua Man

Aqua Man

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I'm also going to toss out some info you may benefit from.

First in soil with lime added or already amended do t bother PHing the nutrients unless you need to for mixing purposes. Such as silicate that can raise PH over 10 and cause other nutrients to precipitate out.

If you insist on it we can have a discussion and would be using citric acid for ph down in soil if ya still think you have to.

Read here for an explanation on how PH is often misunderstood and applied.


This will help you understand how watering is affected by various factors... honestly take the time to read and if you have questions feel free to post it PM me.


And another member had a great idea on how to use the soil meters so they are in the proper zone. Remember any sensor is only going to be effective if placed properly.


Now that you have an overwhelming amount to read I may aswell post some other info on how temp and humidity will affect nutrient uptake and can cause issues leading to deficiencies or water stress.


Ok that about does it for the homework lol. Most of the issues I see relate to those so while it may be a lot of reading it should help you get a bit better understanding of how the moving parts work for plants and environment.
 
Aqua Man

Aqua Man

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Ok i lied... yeah I do that from time to time. Only human ya know.

Just figured this one is also an important read for you.

 
mysticepipedon

mysticepipedon

3,084
263
I'm not seeing a huge pH issue here. Typically, when I've messed up soil pH with too much dolomite or other limestone, I see deficiency symptoms at growing points — usually micronutrient problems with Fe or Zn. I think your main problem is not enough Mg.

Dolomite just can't supply a cannabis plant's Mg needs under LEDs, especially if you don't need to adjust pH. Dolomite is for adjusting pH. Additional Ca and Mg is just an added benefit.
 
oldskol4evr

oldskol4evr

12,306
438
Hello friends. My plants are strain LSD. They are now in about week 12 since sprout and week 1 of flower. The yellowing and drying old growth, and yellow new leaf tips, have been a chronic problem. (I added dolomite garden lime, and not dolomitic lime to the soil, See here)

I water when the leaves droop which has only been about once a up until now. Going forward probably every 4 days. Each time I water a plant gets 1.5 gal, in 5 gal pot (soil). pH I estimate at 6.1 - 6.4 (varies).

A user suggested epsom salt and miracle gro fertilizer for acid loving plant. I only used them once at low concentration.

I use the fox farm trio for nutrients. To one gallon of water I add:
Big Bloom worm castings almost 3 tsp always,
Grow big veg fertilizer, 1 tsp tapering off,
Tiger blüm flowering fertilizer, 1/2 tsp first time last watering (tapering up).
Incredible, right? Sometimes I'll throw some Epson (R) salt crystals in there, but I'm a-scared to go overboard. I'll probably water tomorrow morning!

I suspect I have calcium or magnesium psychosis from the lime I added early on. The leaf stems have been purple for a while, I thought that was from LED lights. Now, in the pictures, I can see some of the main stems are getting red stripes.

Any suggestions on hOw2FiX? I pH with drops, I stand up to pee, and I don't have an EC meter. The plants get tap water. I am authorized to distribute up to $250 in my own personal scrip for the best suggestion. Thank you.
how can you asume it is lime issue? you have know what you got before you can fix,right off .
lime can work both ways,it can and will raise your ph to extreme levels if it isnt applied right, dolimite lime is sweet lime it has sulfur along with magnesium in it,my thought is lack of feed in your case,,next is the mirical grow statment,why why why hahaha stay away from that stuff,i know it is cheap source of food but crap is crap,even manure juice is better than that ,from the combo of the miralce grow,epsome salt and fox feeds your swinging more to lock out.
i have used the trio,this much i know dont go by tablespoons, instead use a tds meter to measure ppm of the feed,use a scale of feeding instead of guess work mate,those plants should be running around 750 to 800 ppm were you are at,1 week of flower and stressed isnt helping your end game,but that game isnt over either,start using the hannah feed scale for feeding,for that matter i dont go over 900 ppm for my whole grow.
epsome salt is great amend for soil users,But it can be over used,once every two weeks is enough,but you still need to know ph , the lime might already have you there on your micro nutrients mate,so check your ph first , you want 6.5 to 7 prefer 6.5,if you got crappy water ph it at 6.5 after you add your feeds to the water.
anyway this could go on for ever but , check your ph first , do a slurry test , that can be achieved with your ph pen
 
TSD

TSD

1,056
163
They look hungry to me, and maybe under watered? They need more water the bigger they get obviously. I used fox farm once, never again, and I don't even use miracle gro on my houseplants lol. Fox farm has pretty packaging, but it worked for shit in my experience. I'm not a fan of liquid nutes in general, though I'm sure there are some good ones out there.. This year I used Dutch Science nutes, it's a powder, one for veg and one for bloom and they also make cal mag, which I used a couple times, but could have lived without it. Shit is expensive if you have several plants but works like a charm.
 
Gurtgurt

Gurtgurt

128
43
I assume it's a Ca or Mg imbalance, or lockout, from the "fast acting lime" that was "derived from dolomitic limestone" (printed on package) that I added early on.

Why did I do that? Because I sampled some runoff water and it was like in the 5s. I added the lime and soil slurry was right at 6.5ish. I've learned since that people say it's pointless to look at soil runoff water. Haven't done a recent slurry test because no distilled water.

I assume this is the problem because that's the only thing I've done differently. I added the lime to new FFOF soil. Beginner's mistake. The yellowing lower leaves and necrotic spots look like online resources for Ca toxicity or Mg deficiency. But I don't know!

I got rid of the pH meter because it was garbage. Could never get a constant reading, even when new and calibrated; the number was always different. I don't have an EC meter because I'm poor.

The lights have been about 30" away until recently, when I switched to flower. I lowered them to 20" and increased intensity. I'll raise them back up.

I will get new flower nutrients if and when I get some money. For now I just have the FF trio and epsom salts.

I will try watering again today with plain pHed water and some epsom salt (which I have used very sparingly until now; based on another recommendation). Any more help is appreciateed!

(Edit: maybe I'll throw some tiger bloom in there, too, since someone said they look hungry)

And BTW I'm not offering US dollars, just my own personal currency which has a terrible exchange rate. It was a joke: I am poor.
 
Last edited:
Aqua Man

Aqua Man

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I assume it's a Ca or Mg imbalance, or lockout, from the "fast acting lime" that was "derived from dolomitic limestone" (printed on package) that I added early on.

Why did I do that? Because I sampled some runoff water and it was like in the 5s. I added the lime and soil slurry was right at 6.5ish. I've learned since that people say it's pointless to look at soil runoff water. Haven't done a recent slurry test because no distilled water.

I assume this is the problem because that's the only thing I've done differently. I added the lime to new FFOF soil. Beginner's mistake. The yellowing lower leaves and necrotic spots look like online resources for Ca toxicity or Mg deficiency. But I don't know!

I got rid of the pH meter because it was garbage. Could never get a constant reading, even when new and calibrated; the number was always different. I don't have an EC meter because I'm poor.

The lights have been about 30" away until recently, when I switched to flower. I lowered them to 20" and increased intensity. I'll raise them back up.

I will get new flower nutrients if and when I get some money. For now I just have the FF trio and epsom salts.

I will try watering again today with plain pHed water and some epsom salt (which I have used very sparingly until now; based on another recommendation). Any more help is appreciateed!

(Edit: maybe I'll throw some tiger bloom in there, too, since someone said they look hungry)

And BTW I'm not offering US dollars, just my own personal currency which has a terrible exchange rate. It was a joke: I am poor.
Just FYI pre amended soils like yours take a while to activate the lime in them. It would be expected for it to be low out of a fresh dry bag. Takes about 2 weeks and then check the ph again after you wet it the forst time.
 
mysticepipedon

mysticepipedon

3,084
263
I assume it's a Ca or Mg imbalance, or lockout, from the "fast acting lime" that was "derived from dolomitic limestone" (printed on package) that I added early on.

Why did I do that? Because I sampled some runoff water and it was like in the 5s. I added the lime and soil slurry was right at 6.5ish. I've learned since that people say it's pointless to look at soil runoff water. Haven't done a recent slurry test because no distilled water.

I assume this is the problem because that's the only thing I've done differently. I added the lime to new FFOF soil. Beginner's mistake. The yellowing lower leaves and necrotic spots look like online resources for Ca toxicity or Mg deficiency. But I don't know!

I got rid of the pH meter because it was garbage. Could never get a constant reading, even when new and calibrated; the number was always different. I don't have an EC meter because I'm poor.

The lights have been about 30" away until recently, when I switched to flower. I lowered them to 20" and increased intensity. I'll raise them back up.

I will get new flower nutrients if and when I get some money. For now I just have the FF trio and epsom salts.

I will try watering again today with plain pHed water and some epsom salt (which I have used very sparingly until now; based on another recommendation). Any more help is appreciateed!

(Edit: maybe I'll throw some tiger bloom in there, too, since someone said they look hungry)

And BTW I'm not offering US dollars, just my own personal currency which has a terrible exchange rate. It was a joke: I am poor.
As I said above, I don't think your pH is way off. Lowering the lights to 20" + being hungry for Mg seems to do this in my grow. Your plants otherwise look very good. This isn't the end of the world for them.
 
Gurtgurt

Gurtgurt

128
43
So, here's my plan. I've raised the lights to maybe 24 in and they are off the ground. From now on I will water with only grow big (veg) and tiger bloom (flower nutes), tapering off of the grow big as flower phase progresses. I'll probably throw some Epson(R) salt in the water too (every so often) for magnesium. I got some baking molasses, maybe I'll start adding some of that to plain water later.

I will pluck any lower leaf that is sick or has no green (then the problem seems to creep up to the next-higher leaf--but usually not as bad).

I appreciate any further thoughts or suggestions. Here's a thought: you know how today we have a "corn maze?" Native Americans used to call corn "maize." Conspiracy?
 
Gurtgurt

Gurtgurt

128
43
Pictures of the worst leaves after last feed of plain water. Cool two-tone leaf in there.
 
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Gurtgurt

Gurtgurt

128
43
Hello friends. I must be in week 5 of flower and I watered today. Here's what the worst leaves looked like. I cut all of them off. I watered with (per gal) 1 tsp Grow Big, scant tsp tiger bloom, 2 tsp molasses, 1/2 tsp epsom salt.
If you think of something I can do different, let me know! I'm out of tiger bloom and will have to get a new supplement.

(Please note that for these pictures, the plants were very limp and needing water earlier today)
 
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OutdoorGrowGuy

OutdoorGrowGuy

45
18
Hello friends. I must be in week 5 of flower and I watered today. Here's what the worst leaves looked like. I cut all of them off. I watered with (per gal) 1 tsp Grow Big, scant tsp tiger bloom, 2 tsp molasses, 1/2 tsp epsom salt.
If you think of something I can do different, let me know! I'm out of tiger bloom and will have to get a new supplement.

(Please note that for these pictures, the plants were very limp and needing water earlier today)
Have you been periodically giving plain water with some runoff?

I might be way off the mark here, but there's a fair amount of room on the pot. You could try a top dressing of fresh ocean forest?
Being soil, a large plant and looks as though been in that pot for a while, it may benefit from a little organic matter.
Don't smother it, though I don't think an inch or two will hurt. It may even help a little.
 
Last edited:
Gurtgurt

Gurtgurt

128
43
Have you been periodically giving plain water with some runoff?

I might be way off the mark here, but there's a fair amount of room on the pot. You could try a top dressing of fresh ocean forest?
Being soil, a large plant and looks as though been in that pot for a while, it may benefit from a little organic matter.
Don't smother it, though I don't think an inch or two will hurt. It may even help a little.
Unfortunately I've used all of my good soil (just as well, I added garden lime to all of it which was apparently a no-no). I will purchase new Soil when I'm able. Thank you for the tips.

I do water with plain water alllmost every other watering... I don't water very often though so I want them to get something.

I think I will start watering more often. I water once the leaves start to droop--pot has been very light for a day or 2 at that point.

Edit: as to your point about organic matter: a fellow here directed I should end the use of FF Big Bloom (worm and bat poop). The fertilizer guide days to use it throughout grow. Should I resume adding that to water? (Even 'plain' water?)
 
OutdoorGrowGuy

OutdoorGrowGuy

45
18
Unfortunately I've used all of my good soil (just as well, I added garden lime to all of it which was apparently a no-no). I will purchase new Soil when I'm able. Thank you for the tips.

I do water with plain water alllmost every other watering... I don't water very often though so I want them to get something.

I think I will start watering more often. I water once the leaves start to droop--pot has been very light for a day or 2 at that point.

Edit: as to your point about organic matter: a fellow here directed I should end the use of FF Big Bloom (worm and bat poop). The fertilizer guide days to use it throughout grow. Should I resume adding that to water? (Even 'plain' water?)
I can't really make that call myself, as I haven't used the product before. But in general those liquid organics work more as a nutrient supplement. I wouldn't rely on them as a source of organic matter.
And I wouldn't go adding any rich organic matter. But see no harm in an inch or two of fresh soil. If it improves a little, you may want to consider a slightly larger pot of soil next time around. Or an intermediate pot before transplanting to it's final size.
 

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