Please Help! Babies are showing yellow new growth!

[Powerz]

Hi all!

Here are some background facts on my babies

-They are about 3 weeks old
-They are in a DIY Deep Water Culture system made from a cooler
-They experienced root rot very early on which I flushed out and treated with peroxide
-They were stunted for a couple weeks and now they are showing new growth but it is ALL yellow!
-When I thought the yellowing was from nutrient deficiency, I added quarter strength nutes which I flushed out the next day when I found out that would burn them.
-the room and res temp fluctuate between 75-80
-They recieve 24 hour lighting under 2 42w 2700k cfls for now.
-pH of res is 6-6.5
-RH 40-60%
-ppm is unknown but using tap water (pH'd)
-the first one is a week younger than the rest

Anything else I may be leaving out please let me know! Thank you guys for all your help and support I really appreciate it!

Please feel free to visit my journal for more pictures or to check out the rest of my grow, thank you!

 

[JJ Bones]

I'd try keeping your water temperature below 75 degrees, preferrably around 70.

It looks like it could be an iron and/or a sulfur defieciency.

Iron deficiency will start with the new growth (as you mentioned) which lack chlorophyll however lack spots also. Aim for a 5.5 - 5.8 pH range.

Sulfur is similar but it distributes evenly throughout the plant.

Try to find some nutrients that contain iron and/or sulfur, Fe and S.