Slow growing seedlings

Isn't the test too dry for it? Try covering with half cut bottle, so it remains in high humidity, and keep all the soil a bit wet, not too wet neither too dry.

And the gnat thing. I highly doubt if you have them unless you got some contaminated soil that was kept outside on a pallet or something. Test your soil. Take a hand full put in a bowl and fill with water soil will sink to the bottom and bugs you should be able to see. Good luck

You also added compost to your soiles peatmoss. When you have a heavy peatmoss mixture and you add composted to that, changes which is the best ph to feed your plants at. Most tap water comes in a little to high for cannabis. You need to read your ph and adjust before watering your girls. with soil and peat mixed together I would be shooting for about a 6 to 6.2 ph and after the composte has diminished its nutrients, you need to have a feed schedule ready to go.

I would be going to 100%, your light ain't that strong. I would also go to 18/6, all plants NEED sleep, cannabis included. Without sleep, plants can not finish their daily photosynthesis cycle and have a correctly functioning metabolism. The MYTH that it is ok to grow cannabis for weeks/months without sleep needs to be removed from history ASAP! Growing at 24/0 could only be recommended by people who do not understand photosynthesis or how plants function either........ Deep watering every few days is much, much better than misting your plants, which does basically nothing, other than prevent death. You want the roots to grow deep and find nutrients to grow properly, otherwise the plants end up stunted from shallow watering (misting). Misting should only ever be used on clones to prevent moisture loss while waiting for roots to form. Cannabis can not absorb water in life sustaining amounts through its leaves. Water flows from the roots, up the plant and out the leaves, not the other way around. Hope this helps, Organoman.