stems growing super long?

What causes stems to stretch during germination and seedling stages?

is it just from having the light too far? seeds have been started in rockwool cubes and the stems have grown so long that the plants need small stakes for support.

ive found some genetics play a roll in this but generally it is from the light being too far with that said ive had some seedlings grow into my fls while the beans next to them stayed short. I know people who grow hundreds of seeds out at a time and use 1000w mh plan for this and use semi rigid wire to hold the little ones up. good luck

its stretching for light, you need a t5 or fluorescent like an inch or two from the top of the plant