Starting in final pots is preferred to me. Obviously the op is watering seedlings way too much. Seedlings that size literally need a couple ounces every other day. Start with cutting back on the watering. You don't need to wet all the soil at this point.
I use 1 inch of a mixture of top soil, cow/chicken manure and vermiculite. The soil itself is full of perlite and very fluffy. I've been using this combination on the top inch of soil for years. It helps retain moisture, provide beneficial bacteria and nutrients. As for pot size, autos have always done best for me if I start them in their final pot or tops the first of 2 pots. The minimum amount of stress to an auto helps alot in yields. I start them off to one side so when I LST them the longest part stays within the pot and I save space for another pot. Also the light(2 samsung lm301h 400mm 24v 48w) is 8 inches away. The par at this height registers around 600 at the "hotspot" which is directly above the plant. She's just a stretcher.
I agree, atleast with autos
I haven't watered it at all and it's in a cloth pot. Your reply popped up right after I replied to green machine so you didn't see that I haven't watered her.