leaves turning brown and curling up

[Smarty]

I could use some help diagnosing my sick plants. Leaf tips turn brown & then it travels to the rest of the leaf.
High pressure aeroponics with metal halides. PH is 5.9, water temp is 69, root chamber is 73, air temp is 83. I use Mills Nutes. I have added Cal Mag. Humidity is around 45%. Plants are 3rd week in Veg. Any thoughts would be appreciated

 

[Blackmidget]

Did you take a look at the sympton checker here in the site?

 

[Smarty]

I did. It looks like a potassium deficiency but I can't see how that would happen, my PH is perfect & I have never had a problem with my nutes, always used Mills.

 

[D.A.A.S.69]

Hey Smarty, I can't see your pot very well, but it looks like she's rootbound to me. She needs a larger pot.

 

[D.A.A.S.69]

I know I got a good buzz going, but I thought I done answerd, that one time, maybe not.

 

[Smarty]

No pot, aeroponics

 

[abadtrip]

Are u useing calmag

 

[Smarty]

Calmag, yes