tops of plants turning a pale green

[Torco]

the tops of my plants are turning a pale green almost yellow. and some of them are curling under, this is just happening to the new tops on the plants. There in the Veg stage now

I only water about once a week when there dry. no nutes for at least 2 weeks
Temp in room is around 80 Deg. Ph is around 6.5

1000 MH light about 20 inches from plants.

 

[Torco]

 

[Torco]

 

[Torco]

the first pic is a large plant. its in im guessing around 15 gallon pot

the second plant is in 4 gallon pot

 

[NoDirtWeed4Me]

I don't really see anything wrong on the first one. Looks like a very healthy and very bushy plant. I would guess with the second that like Carp said it's root bound or it needs a good flushing. I'd suggest both. Flush it really good with enough water that it comes out clean and clear, then transplant it into a larger pot. Neither one will hurt it in the long run and might just save it if either is the cause.

 

[Stix]

I'm having the same exact symptoms in my Hydro Grow. I'm using 2 gallon buckets. My roots were about 18 inches long when I dropped them in the buckets after veg. I'm starting to think I'm having root bound too.

 

[Torco]

transplanted it yesterday, it was very rootbound.