plant going yellow hydro {help}pics

my friend is growing hydro been in for about two weeks he feeds tham evey half hour off and on.hes got 2 1000w hps 2 feet away.thay havnt got any new roots or new groth and there starting to go yellow and some are dieing.thay are on 18/6 if any one can help he dosnt really no whats hes doing.thanks
https://www.rollitup.org/hydroponic...lant-going-yellow-hydro-help.html#post2254413

Mine looked like that because of a zinc deficiency usually caused by ph being off. Should be around 5.5 to 6.5. Could it be that?

pirate420 said:

mine looked like that because of a zinc deficiency usually caused by ph being off. Should be around 5.5 to 6.5. Could it be that?

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he got hes around 6 so i think thats ok any other help would be nice
thanks