Nitrogen def or too much light?

[DogtowN]

I am trying to identify what is the problem. They are under the 600 w HPS from two days and yesterday i move the lamp 1 feet away. The lamp now is two feets away. I fed them today with half strength veg nutes pH 6.3. Curious thing is that i measure the runoff water and is 7.5-8 pH?! Temps 24-25 C day and 20-21 C night RH 50-60 %. Any ideas?

What are you using to measure pH? To see runoff numbers jump so high is odd, to say the least. I doubt those numbers.

Have you seen the troubleshooting form that is posted as a sticky? You should fill it out if you want anything more than just "guesswork" from the board. There are a lot of knowledgeable folks here, the more info you provide the more accurately your troubles can be diagnosed.