Slow growth

My SOG was made up of 8 plants of various sizes and rates of growth, by about 4th week of flower 90% are similar size. How are the roots? As someone said pot looks small, it's roots want freedom. I was told when young plants leaves are wider than the pot it's time to move up. Be lucky, it looks healthy, its all going on underground.. or would be 🙂

I had a few do this at the beginning of the season, I carefully dug down into the roots and loosened them and the soil around them up and they started growing normally. Maybe it's just the picture, but the pot looks tiny maybe just needs to transplant for my root space.

Take a temp at canopy level, maximal photosynthesis occurs at a leaf surface temperature of 86. Set ambient temp of grow space toooooooo 83 ish and get the light as close as you can to make it 86 lights on. Make sure to keep a nice wet/dry cycle going. If you have digital scales you can even measure water that way its very accurate. ( given all other cardinal rules for plant growth are me) you should notice a difference.

looks healthy... 10-14 days is about right for that... growth increases exponentially, at least fo a bit.... just a slow roll to start. once you hve more solar panels, the plant can grow more. it could be 3x that size in 5-7 days.... and 3-5x that size in another week. Light should be based on resulting internode length. don't let them get too large or stay too tight and you'll be fine. don't baby it too much. 30cm is pretty close with a qb-type board. so even at 25-percent it seems to be getting plenty... it doesn't look stretched out or anything. i see see a little oddity in your substrate that leads me to think you need to adjust your irrigation habits with coco/perlite mix (a "soilless" medium). The first 10-14 days the seed will power itself.. the cotyledons will pale as a sign it's definitely ready for fertilization. i give at least some fertiliation from start, although slightly watered down from normal... seeds gow fine in the wild where the earth is never devoid of nutes... as long as you don't overdo it, it is fine... it's like planting in fertile soil outdoors. so, fertilize every single time you irrigate. i see dryness around edges with a more wet center.. make suer you saturate entire volume of substrate. dry pockets that re-occur are a potential cause of buildup. If you are religioous about fully saturating and having 10-15 percent runoff waste, you will never have a buildup of nutes in your substrate. so make sure teh whole damn thing gets wet and another 10% of what you dumped in runs out bottom (waste water or okay for outside garden)

you're fine, consider transplanting soon.