off-gassing or magnesium

[RedBeardy5]

I have been having a problem that I cant fix. Im growing in coco with 1000 watts vertical. I have been feeding them h&G nutes and never have problems until now. This is my first run with my room being sealed so im thinking its off gassing. So members told me to drop the cal/mag and add just mag which makes sense but the problem just progressed.

 

[RedBeardy5]

 

[RedBeardy5]

 

[RedBeardy5]

 

[RonSmooth]

That looks like Mg deficiency but doesn't necessarily have to be from lack of Mg. Improper pH levels, unhealthy root systems, over feeding/watering, heat & moisture stress and other environmental factors can inhibit the plants ability to use available nutrients.

The hooked/burnt leaf tips are found in calcium deficient plants but I don't see the tell tale spotting of common Ca def.

The two often occur together because they are found in a lot of tap water around the country. If you use tap water and have water with minerals present in sufficient quantities, you can get by without additional supplementation of these elements.

If you use RO water or have "soft" tap water, you will end up with Ca and MG deficiencies; usually in flower as the plants use a lot during this stage.

I have soft water (50 ppm) so I add calmag to bring it up to around 150 ppm before adding my nutrients.

What is your water source?

 

[RonSmooth]

and whats with all the off-gassing threads I have been seeing?

this is my answer to that question.

it isn't "off gassing".

ever.

 

[RedBeardy5]

Well my grows have been great and nothing has changed other than sealing the room. What makes me believe its off gassing is bc the problem gets worse when it gets over 80 degrees. formaldehyde concentrations rise as heat and humidity rises. With c02 I should be able to run 85 degrees no problem. Its a deficiency I have never seen, there are like round green patches.

 

[RedBeardy5]

I have been trying to fix it for 3 weeks, went over everything and am throwing my hands up here.