I’m not growing in RDWC anymore, it’s just a clay pellet media drip fed and recirculated. I should switch back but I have it set up this way and am too lazy to plumb everything back up.. I do still do them in collars sometimes, I just wait till they have a good handfull of roots.
Sometimes it's smarter to do just that and cut your losses rather than deal with stunted plants occupying your space. I just watched a Mr. Grow-It YT podcast where he was talking to a guy who grows huge autoflowers in 8 inch rockwool cubes. He says he regularly pulls the stragglers if they aren't performing as he wants. I wish I could afford to do that. I've got 1 plant out of 4 that is less than half the size of the largest from the same strain. If I didn't have these clones fighting for room, I'd chop that one. My autos are just starting to pop pistils. I scratched in some flowering nutes last night and watered in a little epsom salts as I usually start seeing Magnesium deficiency around flower time. Hoping to do better this round. Foliar sprayed Epsom salts on the clones too. They were looking bad.I'm going to cut my losses and start fresh next week. There's no way these 2 little plants will grow enough before they start to flower.
I think my problem has been the medium I've been starting my seeds in. After seeing the post by @Mumbeltypeg questioning what I was using to start my seeds in I did some research. I found out that it's a product from ihort called a q-plug. I think it's too dense and hinders the roots and substantially slows the seedlings growth.