Why wont 2 out of 3 grow like normal

Quick question. Im growing ww x bb 3 of them. One of them seems to be growing pretty smooth the other 2 looks like they havent grown in a week. Im on day 21 of vegetation. Im usong 1 600 mh bulb in a room down cellar. Im using dyna gro for nutrients and distilled water

Not all plants of the same strain will grow the same, even clones can grow at different rates.

Seeds are like people. Each are totally different

So just let it do its thing and wait

I grew 6 generation s of W W and each grow was deferent. Don’t figure genetics I do believed is to blame

Will