Deficiency under LEDs?

So I'm new to growing under cobs and have never got these deficencys under hps. My plants are in straight foxfarm happy frog witch usually gets me threw my vegging cycle without food. I've been given straight RO water. A buddy of mine that grows under cobs said they would need more calmag but it was probably magnesium. So I just treated with ph'd tap water with a teaspoon of Epson salt. Lol I probably should of posted this before I treated but thought I would see what y'all thought. Thank yall

Yep Mg def.

Cool beans

Classic Mg def.

Yep defiantly Magnesium.

I used to run more light than I needed when I first built the cob build. I've since backed down to around 40w sq ft input with an ~18" distance. Much less deficiency issues. ymmv

Lol this is my first round under Leds so they where at 20w a foot at about 30 inches away its still at 30 away but ive bumed up my wattege per square foot to somewhere around 35w a foot.

dandyrandy said:

I used to run more light than I needed when I first built the cob build. I've since backed down to around 40w sq ft input with an ~18" distance. Much less deficiency issues. ymmv

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oilfield bud said:

Lol this is my first round under Leds so they where at 20w a foot at about 30 inches away its still at 30 away but ive bumed up my wattege per square foot to somewhere around 35w a foot.

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I run 16 3590's at around 350 watts and 80 watts of 660 nm in a 42"x42" area. Then after they fill in the area is 42" x 60". The extra space I light with three quantum boards after they fill the area. I've ran the cobs for 4 years now.

That's badass man. I just built my first cxm22 rigs. I've got 3 on 320h54a drivers running 4 cobs each in a different tents. 2 of witch are for vegging and one is gonna be a lil seed making project. Also am working on a 24 cob fixture running 1800w off of 3 hlg 600h54bs it's gonna be a monster