Don't use nutrient on the rockwool. Lettuce doesn't like that. Use plain tapwater but ensure that the pH is less than 7 (±6.5)
Once the seedlings seem established, use nutrient at ± ¼ strength.

So i need to cut to 1/4 strength on my nutrient? I don't put nutrient on them until after the first week or so (when they get a leaf or two. So I still should keep my hydroponic system at full strength nutrient right?

the roots on the rockwool are almost nothing while the ones planted in trays are growing out the bottom

Difficult to judge without seeing. Still think you should reduce the strength of the nutrients, but maybe . . . something else might be at work. Can't say.

it it possible for seedlings in rockwool to get too much water?

They have been sitting in 1/4" of water in a tray

higgins, there's no shortcut to this. My reason for lowering the nutrient content is the fact that the roots are very short, which usually means: too much nutrients.
So . . I suggest to put the seedlings on plain water for a while. Would say: a week. Then see what happens.

ok i'll cut the nutrient on all seedlings and the ones i started in the NFT sytem too

thanks
Higgins

Lettuce is a light feeder in hydroponics. I don't know what nutrients you are using but the stuff I use is a dry powder where their normal "full strength" is 1 tsp per gallon of water. I've found that established lettuce seedlings can take a very weak (less than 1/4 tsp per gallon) of this and my "full strength for lettuce" is like a 1/2 tsp per gallon. I try not to go over a CF of 12 for my lettuce.
The 1 tsp per gallon usually came our around a CF of 18 for me which is more appropriate for my cucumbers.