Leaf Discoloration

[zoneman2]

Hello,

I'm growing Autos in a Coco/Coast of Maine Stonington Blend mix 7 gal pots fabric. I think it may be a CAL or MAG issue. What do you all think? I keep the water PH between 6.4-6.6. I add Blackstrap Mol every other watering. If you need any more information just ask. Thank you.

 

[OldMedUser]

Not Mg but could be a Ca issue. If that's as bad as it gets I wouldn't worry about it much.

 

[zoneman2]

Not Mg but could be a Ca issue. If that's as bad as it gets I wouldn't worry about it much.

I was also thinking it was mainly a Ca issue also but since Ca Mg almost go hand in hand that why i suspected maybe Mg also. I'll keep an eye on it for the next few days and see what happens. If it does get worse do you suggest eggshell or Epsom salt tea to make into a spray or something else?

 

[OldMedUser]

I was also thinking it was mainly a Ca issue also but since Ca Mg almost go hand in hand that why i suspected maybe Mg also. I'll keep an eye on it for the next few days and see what happens. If it does get worse do you suggest eggshell or Epsom salt tea to make into a spray or something else?

Low Mg shows as yellowing between the veins on the oldest fan leaves first as it's a mobile nute and the plant is stealing it to use it upstairs where it's needed. Ca is immobile so when low tends to show up first in newer growth as the plant can't steal it from the older leaves. Only NPK, Mg amd Zn are mobile. Everything else is fixed in place once used so the plant needs to get those from the roots and if missing or locked out by the pH being out of whack, (generally too high), then symptoms show up first in newer growth.

Eggshell is very slow release calcium and best used in organic type grows where the soil is 'cooked' for some time before used with plants. Any decent CalMag will get Ca to the plant right away and supply a balanced amount of Mg along with it. Get one with iron as that's a common mineral that can end up in low supply too.

Epsom salts don't have any Ca so won't help with that but is a great way to get extra Mg when needed and supply lots of S which is why it should be used in later flowering to promote resin production. Very hard to overdose sulphur. Some extra Zn helps with that too so I'll grind up Zn tabs during the grow even in veg to help with all sorts of reactions going on as it acts as a catalyst to help in many areas. Most of us humans are low in Zn, Mg and many other minerals as well as are plants.

 

[zoneman2]

Low Mg shows as yellowing between the veins on the oldest fan leaves first as it's a mobile nute and the plant is stealing it to use it upstairs where it's needed. Ca is immobile so when low tends to show up first in newer growth as the plant can't steal it from the older leaves. Only NPK, Mg amd Zn are mobile. Everything else is fixed in place once used so the plant needs to get those from the roots and if missing or locked out by the pH being out of whack, (generally too high), then symptoms show up first in newer growth.

Eggshell is very slow release calcium and best used in organic type grows where the soil is 'cooked' for some time before used with plants. Any decent CalMag will get Ca to the plant right away and supply a balanced amount of Mg along with it. Get one with iron as that's a common mineral that can end up in low supply too.

Epsom salts don't have any Ca so won't help with that but is a great way to get extra Mg when needed and supply lots of S which is why it should be used in later flowering to promote resin production. Very hard to overdose sulphur. Some extra Zn helps with that too so I'll grind up Zn tabs during the grow even in veg to help with all sorts of reactions going on as it acts as a catalyst to help in many areas. Most of us humans are low in Zn, Mg and many other minerals as well as are plants.

View attachment 4629008

I did notice after that what i was reading was for Mg and sulfur with the Epsom salt not Ca. I have GH Calmag but its not organic. I'm thinking of ordering a bottle of the organic version or going to a local retail store and buying Calcium pills to crush up and add to water if i do see it getting worse. What I read online was to take 10 clean egg shells, Boil some water and then let the water cool a bit. Place eggs shells in the water over night then strain and use but Ca tabs may work better ‍. Thank you for your time and sharing your knowledge.