Yellowish discoloration along the veins of the new leaves

[Smootherpete]

It is a DWC, roots are fine, plant is getting tap water that I let stand for a week almost. GH 3 part nutrients (I keep it at around 2.2 EC) I balance pH at 5.8. My tap water is 0.3 EC so I add cal-mag 'till I hit 0.5, then add nutrients. My question is, what am I doing wrong!? I know this discoloration is not normal even though the plant seems to be doing great, second week of flowering and buds are everywhere. She is a monster with a 1" diameter stem.

 

[Mobileaudio25]

Looks a little like a mag deficiency. Are you using ro/distilled water and putting a cal/mag additive back into your water?

 

[Smootherpete]

Looks a little like a mag deficiency. Are you using ro/distilled water and putting a cal/mag additive back into your water?

No, regular tap water that i let stand a week prior to using. Tap water is 0.3 EC so I add Cal-Mag until it gets to 0.5 then I add my nutrients untill water is 2.0 EC.

 

[amgprb]

Where is it located on the plant? I just recently had this problem. It was only affecting the top of the plant. I realized that it was bleeching. My lights were a bit to close. I moved em up 6 inches and it stopped. (The affected leaves will not correct themselves, but the new growth did not have it)

 

[Smootherpete]

Only the top of the plant was affected. I was suspecting that it was too close to my 600W HPS and already moved the light up, hope that's all it was.