Looking for a little help, please!

Hey guys, I have a 24 plant RDWC system under 2600 watts of light. They seemed happy for a day or two and then I noticed the leaves curling and turning a lime green color. I'm sure its not healthy, im just not sure whats wrong. I'll be attaching some pictures.
The plants are clones just a few days old.
I have a youtube page you can visit to check out the set up. I just checked the PH a moment ago and it was 5.9 with 377 PPM water. When I received the clones I checked the PH of the water and it was over 7! Over a few days I slowly PH downed them to 5.8

Youtube link: http://www.youtube.com/watch?v=US33Q4iNeVc

Looks like a zinc deficiency.. Flush with clean ph'd water.. Give it about half the nutrients you have been giving her

This is a picture of a zinc deficiency.. See a resemblance?

http://www.growweedeasy.com/sites/growweedeasy.com/files/zinc-deficiency-cannabis.jpg

A bit, I do. I was going to flush the system and add fresh water, so, I'll do that. Thanks for the reply!

Any more ideas? Just curious as I like learning, these photos are with my HPS turned off.

It might be a sulfur deficiency.. But i think flushing should fix all her problem's

If you want to learn more about plant issues, visit this site... I literally learned half the stuff I know today from this site..

Good luck..

http://www.growweedeasy.com/sulfur-deficiency-cannabis

Visit this

Thanks Spartacus! I think what was going on was I had essentially emptied my reservoir into the buckets and then turned off my recirculating pumps so it would just be a "DWC" system while I let the roots develop. I think that may have caused the water to become stale or whatnot. I turned the pumps back on and added 10 gallons of fresh 5.8 PH water and they seem to be perking up. Tomorrow I drain the whole thing and add new water. Thanks again for the help and the link, Spartacus.