Does this look like magnesium deficiency to you?

A

AutoPotEnjoyer

Member
Hi everyone! Does this look like magnesium deficiency to you?

A bit about the grow: I'm growing 4 white label Northern Lights fem photos in 5 gallon autopots with fabric bags. The plants are in their first week of flower and were vegged for about 5 weeks. For the grow medium, I'm using 50/50 coco and perlite.

The coco is the brick type prepared in the following way: I washed and filtered it to eliminate coco dust, then I soaked it in 7.5ml/gal calmag water in 100-115F temps for several days (5 gallon buckets in the desert sun). I then changed the water with new 7.5ml/gal calmag water and soaked it for several more days in the sun. Prior to using the coco I rinsed it thoroughly with tap water then did an RO rinse.

I'm growing in a 4x4 tent with a MedicGrow Fold-6 660W light at 80% power. Temp and humidity are controlled at 73F-78F and 60% RH.

I feed using GH FloraMicro, FloraGro, FloraBloom, Calimagic, Liquid Koolbloom, and Floralicious Plus. I follow the GH weekly medium feed chart exactly except I always add 5ml/gal Calimagic. I'm targeting the lower end of the the TDS for each week. I'm on flower week 1, which is 800-1000 TDS. I'm targeting 800-850 TDS.

The water I use is commercially produced and sold RO water. I buy it in jugs and my TDS meter (a BlueLab pen) reads 0.

I adjust the pH in the reservoirs twice a day and I adjust it down to 5.5 using a BlueLab pH meter and GH pH Down. I know 5.5 may sound low and I understand that's the ideal target pH for autopots - apparently the pH rises along the way to the root system.

A couple of days ago I noticed lightening on the leaves between the leaf veins. Now some light spots have appeared.

Pictures I've seen online and in charts makes me think this is a magnesium deficiency, despite the 5ml/gal Calimagic.

To address the deficiency, I understand Epsom salt is the ticket. I had trouble finding dosing information for this sort of thing, so I'm kind of winging it.

I mixed 1/2 tsp Epsom salt in 1 gallon of RO water with a drop or two of everything-free dish soap as a wetting agent. I used this as a foliar spray last night and again this evening, hosing down the top and bottom of the leaves.

In addition, I've added 1/2 tsp Epsom salt per gallon of water in the res and raised the TDS from 800 to 850. I'm still feeding 5 ml/gal Calimagic.

By my scale, 1/2 tsp of Epsom salt is about 2.5g and 1/2 tsp/gal in RO water yields a TDS of 210.

I'm hoping the spots go away and the plants don't just burst into flames or anything.

Thoughts, advice? Thank you!
 

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Nutty sKunK

Nutty sKunK

Well-Known Member
Magnesium is mobile so usually it’s the lower/mid fans that yellow between the veins and progresses upwards.

Your yellowing is occurring on the upper leaves near the tips. Which means it’s most likely an immobile nutrient, too many nutes in media or light is too strong.

If the Epsom salts don’t resolve the issue it’s obviously another factor.

Have you used this set up before with no previous issues?

Couple of things I noted was low pH 5.5 and the use of RO water
 
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beefninja97

Active Member
I'd be really surprised if adding epsom salt to that regimen would make any kind of difference. You already have the trio + calmag. The red stems can indicate a phosphorus uptake issue.

My guess is it's more likely to be excess calcium leading to various lockout (mag, k, p), and so I would actually back off the calmag to like 2mg/gal. Or maybe even drop it altogether. Trio already has calmag in its base nutes. But you are using RO so I'm not sure.

Probably wouldn't hurt to roll back the base as well. Esp since your ppm is astronomical already.

also probably don't want to RO rinse your buffered coco, you will unbuffer it. Just prime it with the nutrients you will be using.
 
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manfredo

manfredo

Well-Known Member
beefninja97 said:
I'd be really surprised if adding epsom salt to that regimen would make any kind of difference. You already have the trio + calmag. The red stems can indicate a phosphorus uptake issue.

My guess is it's more likely to be excess calcium leading to various lockout (mag, k, p), and so I would actually back off the calmag to like 2mg/gal. Or maybe even drop it altogether. Trio already has calmag in its base nutes. But you are using RO so I'm not sure.

Probably wouldn't hurt to roll back the base as well. Esp since your ppm is astronomical already.

also probably don't want to RO rinse your buffered coco, you will unbuffer it. Just prime it with the nutrients you will be using.
Click to expand...
This sounds correct to me. I'm, going through the same thing in my coco grow, in veg, and also using GH.

After trying spraying with calcium and magnesium and getting zero results, I then thought lockout (along with some help) Did a thorough flush using Flora clean yesterday and they are looking better already. I'm going to feed them today and hope the issue is resolved!

Also, 5.5 is not low for coco....5.5-6.5 is the correct range, Try a flush, especially if you haven't been watering to runoff.
 
manfredo

manfredo

Well-Known Member
AutoPotEnjoyer said:
Hi everyone! Does this look like magnesium deficiency to you?

A bit about the grow: I'm growing 4 white label Northern Lights fem photos in 5 gallon autopots with fabric bags. The plants are in their first week of flower and were vegged for about 5 weeks. For the grow medium, I'm using 50/50 coco and perlite.

The coco is the brick type prepared in the following way: I washed and filtered it to eliminate coco dust, then I soaked it in 7.5ml/gal calmag water in 100-115F temps for several days (5 gallon buckets in the desert sun). I then changed the water with new 7.5ml/gal calmag water and soaked it for several more days in the sun. Prior to using the coco I rinsed it thoroughly with tap water then did an RO rinse.

I'm growing in a 4x4 tent with a MedicGrow Fold-6 660W light at 80% power. Temp and humidity are controlled at 73F-78F and 60% RH.

I feed using GH FloraMicro, FloraGro, FloraBloom, Calimagic, Liquid Koolbloom, and Floralicious Plus. I follow the GH weekly medium feed chart exactly except I always add 5ml/gal Calimagic. I'm targeting the lower end of the the TDS for each week. I'm on flower week 1, which is 800-1000 TDS. I'm targeting 800-850 TDS.

The water I use is commercially produced and sold RO water. I buy it in jugs and my TDS meter (a BlueLab pen) reads 0.

I adjust the pH in the reservoirs twice a day and I adjust it down to 5.5 using a BlueLab pH meter and GH pH Down. I know 5.5 may sound low and I understand that's the ideal target pH for autopots - apparently the pH rises along the way to the root system.

A couple of days ago I noticed lightening on the leaves between the leaf veins. Now some light spots have appeared.

Pictures I've seen online and in charts makes me think this is a magnesium deficiency, despite the 5ml/gal Calimagic.

To address the deficiency, I understand Epsom salt is the ticket. I had trouble finding dosing information for this sort of thing, so I'm kind of winging it.

I mixed 1/2 tsp Epsom salt in 1 gallon of RO water with a drop or two of everything-free dish soap as a wetting agent. I used this as a foliar spray last night and again this evening, hosing down the top and bottom of the leaves.

In addition, I've added 1/2 tsp Epsom salt per gallon of water in the res and raised the TDS from 800 to 850. I'm still feeding 5 ml/gal Calimagic.

By my scale, 1/2 tsp of Epsom salt is about 2.5g and 1/2 tsp/gal in RO water yields a TDS of 210.

I'm hoping the spots go away and the plants don't just burst into flames or anything.

Thoughts, advice? Thank you!
Click to expand...
Also wanted to say your plants are looking good, and welcome to RIU :bigjoint: Well written post!!
 
T

Treesomewanted77

Well-Known Member
I would flush as stated above. Those auto pots don’t allow you to get the access salts washed out because they are a bottom feed system. Also the additives your adding aren’t really needed especially the Floralicious Plus that stuff is meant to keep well aerated and is highly organic probably not the best thing for a hydro grow.
 
A

AutoPotEnjoyer

Member
Nutty sKunK said:
Have you used this set up before with no previous issues?
Click to expand...
Yes, kind of. I have 3 4x4 tents, all set up the same way with AutoPot XLs. I try to keep all variables as close to possible between the tents. Each grow I learn more about what not to do. So far I've run into issues with each grow, but I'm doing fewer things catastrophically wrong each time, so that's progress.
  • I harvested my first grow using this method a month ago. I grew Ethos Apex R-1 and absolutely scorched them due to over feeding. This stunted them and clearly hurt the yield. Despite my mistakes I pulled 20.5 oz dry from the harvest and I really like the end product.

  • I'm harvesting white label (ILGM) Grandaddy Purple this weekend. I managed not to burn these but did overfeed early in the grow, which left the tips of some of the leaves burned and curled. During this grow I followed the Calimagic feeding guidelines based on the GH guide exactly. In the first week of flower I ran into what looked like to me a calmag deficiency. I upped the dosage to 5ml/gal then and the problem went away after about a week. Since then I've kept the Calimagic at 5ml/gal for all my grows. I'm pretty happy with how it looks like they turned out - they're 5' tall now and I was afraid I'd run out of room.

  • In addition to this Northern Lights grow, I'm also growing Ethos Citradelic Sunset using coco from the same batch. I haven't seen any issues with them yet and hosed them down with some Epsom salt as a prophylactic measure anyway.
I've attached photos of the GDP on the first week of flower before I upped the calmag and a photo of them today.

Thank you!
 

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A

AutoPotEnjoyer

Member
Treesomewanted77 said:
I would flush as stated above. Those auto pots don’t allow you to get the access salts washed out because they are a bottom feed system. Also the additives your adding aren’t really needed especially the Floralicious Plus that stuff is meant to keep well aerated and is highly organic probably not the best thing for a hydro grow.
Click to expand...
Maybe. I use Floralicious Plus for the sole reason that it's on the GH chart and as a bonus it turns the water brown. Let me warn everyone from my experience, though - don't spill a bottle of the stuff in your grow room. It's an oozy black liquid that seeps everywhere and it makes low tide smell pleasant by comparison.
 
T

Treesomewanted77

Well-Known Member
AutoPotEnjoyer said:
Yes, kind of. I have 3 4x4 tents, all set up the same way with AutoPot XLs. I try to keep all variables as close to possible between the tents. Each grow I learn more about what not to do. So far I've run into issues with each grow, but I'm doing fewer things catastrophically wrong each time, so that's progress.
  • I harvested my first grow using this method a month ago. I grew Ethos Apex R-1 and absolutely scorched them due to over feeding. This stunted them and clearly hurt the yield. Despite my mistakes I pulled 20.5 oz dry from the harvest and I really like the end product.

  • I'm harvesting white label (ILGM) Grandaddy Purple this weekend. I managed not to burn these but did overfeed early in the grow, which left the tips of some of the leaves burned and curled. During this grow I followed the Calimagic feeding guidelines based on the GH guide exactly. In the first week of flower I ran into what looked like to me a calmag deficiency. I upped the dosage to 5ml/gal then and the problem went away after about a week. Since then I've kept the Calimagic at 5ml/gal for all my grows. I'm pretty happy with how it looks like they turned out - they're 5' tall now and I was afraid I'd run out of room.

  • In addition to this Northern Lights grow, I'm also growing Ethos Citradelic Sunset using coco from the same batch. I haven't seen any issues with them yet and hosed them down with some Epsom salt as a prophylactic measure anyway.
I've attached photos of the GDP on the first week of flower before I upped the calmag and a photo of them today.

Thank you!
Click to expand...
The main thing is your learning.
I have a couple autopots and use them as a drain to waste setup now and then. I tried running them as directed at the beginning but grew bored with it and wasn’t impressed with the growth rate so I just put a plant riser in the base and top feed to runoff and works great. I since have switched to a bucket company kit but still use the autopot bases for my clones and some veg plants.
Your doing fine with them so far just remember that the feed charts from nutrient companies is far to hot so you want to start with 1/4-1/2 what they recommend. With cannabis less is more on the feed
 
T

Treesomewanted77

Well-Known Member
AutoPotEnjoyer said:
Maybe. I use Floralicious Plus for the sole reason that it's on the GH chart and as a bonus it turns the water brown. Let me warn everyone from my experience, though - don't spill a bottle of the stuff in your grow room. It's an oozy black liquid that seeps everywhere and it makes low tide smell pleasant by comparison.
Click to expand...
I use it on my outdoor soil plants now and then. Yes it’s so dark and smelly lol I can only imagine what a floor full of it smells like
 
A

AutoPotEnjoyer

Member
Hi everyone! Thanks again for all your help.

Here's a quick update on this issue one week later.

Actions
I took two actions to address the issue:
  • I sprayed the plants several times with Epsom salt - at first 1/2 tsp/gal then at 1 tsp/gal. I did this nightly for a while, then stopped.
  • I added 1/2 tsp/gal to the reservoir and reduced calmag slightly
When I refilled the reservoir I did not add Epsom salt and went back to my normal calmag schedule.

Results
The plants are growing really well overall. I've had to raise the lights and, other than this deficiency, I see no other problems.

The light spots on the leaves worsened for a few days, then slowed greatly. Some brown spots appeared but have stopped. I don't know if the issue is actually resolved or not - I get the sense this will be an ongoing issue and it's something I'll have to watch.

I noted some light burning of leaf tips. I may have gotten overzealous with the foliar spraying - that or perhaps adding the Epsom salt to the res was overdoing it. I've dropped back to 800 PPM and am foliar spraying once a week going forward. The damage looks minor.

IMG_20230907_153009499_HDR.jpg
Plants now (9/7)		IMG_20230907_155925549.jpg
Leaf now (9/7)		IMG_20230903_083501152.jpg
Leaf on 9/3
 
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