is this Mg deficiency?

[VladTheInhaler]

Hi, I have these plants in veg for a month or so, they're supposed to be 'Thai Sticks' (I was unable to find anything about the strain, the technique I'm familiar with), anyway it's a sativa-indica mix, according to the guy that gave them to me (free).
I had a thrips outbreak, but took care of it with spinosad.
I have them in soil mix, and I give them 7-3-6 mineral fertilizer once a week. Current pH is 6,5 -7, measured with soil probe.
I've noticed that veins are kind of darker than the edges of leaves, as seen in pictures below:

Is this magnesium def? I'm still learnig the ropes, and I'm not sure. Please help

 

[Bumble Buddy]

Appears to be interveinal chlorosis which is a possible symptom of magnesium deficiency.

 

[VladTheInhaler]

I have a concentrate with most micro elements (MgO 2,4%, Fe 0,8%, Cu 0,45%, Mn 0,12%, Zn 0,06%, Mo 0,14%, B 0,12%)
The recommended dosage for this is 0,5 mL per 2 l of water. Should I up the dosage, considering the state of my plants?

 

[VladTheInhaler]

Adding double concentration than suggested by the manufacturer didn't help my plants, the signs of Mg def are getting worse.
Can someone recommend a solution to this problem?
Note: I potted my plants into store bought soil, without mixing any garden lime in it, probably a mistake.

 

[Hazeseeker]

Hi Vlad,
go to your local Chemist/Drug Store and buy some Epsom Salts, 1 heaped tablespoon per 5 litres of water(disolve the 1 tablespoon of Epsoms in a small cup of hot water 1st to make sure it disolves then add it to the 5 litres), or if you want the Epsoms to work quicker you can foliar mist - 1 level teaspoon/1 heaped teaspoon per litre of water, spray just after lights out, spray every 3 days until you see the plants starting to improve

 

[VladTheInhaler]

Is epsom salt the same thing as magnesium sulfate? I'm not sure ho we call it in my country.

 

[spiral]

Hey Vlad, yes magnesium sulfate is the same thing as epsom salts.

 

[VladTheInhaler]

Hi Vlad,
go to your local Chemist/Drug Store and buy some Epsom Salts, 1 heaped tablespoon per 5 litres of water(disolve the 1 tablespoon of Epsoms in a small cup of hot water 1st to make sure it disolves then add it to the 5 litres), or if you want the Epsoms to work quicker you can foliar mist - 1 level teaspoon/1 heaped teaspoon per litre of water, spray just after lights out, spray every 3 days until you see the plants starting to improve

I have the lights on 24/7, is it safe to mist the plants? I use cfl for veg faze.

 

[knna]

I have the lights on 24/7, is it safe to mist the plants? I use cfl for veg faze.

Yep, ive never seen a burn due a CFL light though a drop of water (and rarely from a HID).

If you suspect the soil is really bad, now you can transplant them with a better soil, so you can add a bit more limestone and perlite (it improves soil aeration and does more difficult to overwater), about 25-30%.

 

[rule35sub1]

Solution to fixing a Magnesium deficiency
Any Chemical/Organic nutrients that have Magnesium in them will fix a Magnesium deficiency. (Only mixing at ½ strength when using chemical nutrients or it will cause nutrient burn!)
Other nutrients that have magnesium in them are: Epsom salts, which is fast absorption. Dolomite lime and or garden lime (same thing just called different) which is slow absorption. Sulfate of Potash, Magnesia which is medium absorption. Worm Castings, which is slow absorption. Crabshell which is slow absorption. Earth Juice Mircoblast, which is fast acting. (a must buy!! Has lots of 2ndary nutrients).
Now if you added to much chemical nutrients and or organics,( which is hard to burn your plants when using organics) You need to Flush the soil with plain water. You need to use 2 times as much water as the size of the pot, for example: If you have a 5 gallon pot and need to flush it, you need to use 10 gallons of water to rinse out the soil good enough to get rid of excessive nutrients.