your lamp in all likelihood, is a "triphosphor" means that inside the lamp is a little bit of mercury that emits u.v. - the u.v. strikes the phosphor on the side of the lamp, and visible light is re-emitted. the tri part of it means there are three different phorphors, one blue, one red, and one yellow/green so your lamp will emit light in a line spectrum with all three components. All high quality modern fluorescent is like this - the spectrum output shows three spikes, and your lamp, even though 6500k, still will have a red spike in it, so don't worry, you are fine.

Thanks, overdrive. It just may be that that form of lettuce grows in that fashion.

I have grown mixed lettuces and many different . If your musclun mix includes endive or watercress--not typically lettuce but often included with them--they will grow in that spindly way. Oriental lettuce will also not have those big leaves that we associate with lettuce.

I don't think your lights are to blame. I think it's the seed that's growing like it is meant to. I wouldn't change a thing about you lights

Thanks, dow.

Hello over drive, can you post some pics of your lettuce please?

i don't have any lettuce but i will take some pics of my tomatoes - i will do that in a few days - need to take pics for horticultural society meeting as well - thanks - pm.