I just thought my lettuce was the wrong type since I saw similar growth to that in the pictures. I know the youtube videos showed nice tight heads, and that is why I started doing this. I just ordered more rock wool cubes and now I'm hearing they cause root rot. If I start
seeds in vermiculite and transfer healthy seedlings to rock wool, I have already doomed my plant?
I am taking the rock wool cubes and putting them in net cups and a tub with air stones. They continue to grow and produce long leaves, but not the nice tight heads. The stems don't look rotted, but seem weak at the top of the net pot. I have them in a small greenhouse with natural sunlight.
I just started bib lettuce because I read an article posted somewhere by University of Fla saying bib was the answer to less than perfect weather variations in Florida. My winter temps frequently are above 80 but they can also get to 30 for a night or two. Thus the greenhouse with a space heater on a thermostat.
I appreciate the comments here since I am new to hydroponics.