What is your light source?
I have florescent tube lights
long lettuce like that is a sign of not enough light. The plant is stretching to try to reach the light.
Much brighter light would work.
Or you need the florescent tubes to be about 2 inches from the leaves and you need to be sure they are the higher color temperature florescent tubes. There is a group on artificial lighting and those guys can probably help you with details about what kind of light is needed to effectively grow plants indoors.
Thanks I'll look into that
I have T12 lights also, (just like you), the brighter your source, the better your stuff will grow. If you have like 5 T5 lights, it would work better (especially if they are daylight deluxe lights). My romaine luttice did the same thing as your luttice is doing and I was using two T12 lights. Hope this helps
Thanks Dan I only have two lights right now so I'll try more Thanks
i have 2 hoods with 2 t12 fl's in each over a 3x5 space and my plants (ie. lettuce, basil, cilantro, spinach) are doing great. i have noticed that the outside spinach does better however. also i tried daylight deluxe lights and they really sucked. get growlights they r worth the extra money. also important (i recently found out) is the hood. i had a really cheap walmart hood with no "wings" at the sides, then i switched to a hood i found at a garage sale (2$!!! yea!!!). i had to do some wiring and painting, but it works great. it is one of those hoods u mount on the ceiling. oh, also i keep the lights as close to the canopy as possible and adjust as needed. i am thinking of switching to t8's soon for the energy savings. i am trying to stick with lighting that is readily available to me otherwise i would think about another option.