They look good man, tbh I wouldn't worry to much about the soil, yes you should add perlite but if I where you I would get some good nutes off amazon or eBay along with ph up and ph down with the ph test dripper and do a hempy bucket grow its a form of hydroponics ( passive hydro) great for beginners just do some searching out it a lot of people do a 1-3 ratio of vermiculite and perlite both can be bought at lowes or home depot for less then 10$ together. Now I believe you said you are using mg soil, ok a lot of people might not like that I am saying this but mg soil is great soil for its price but Its not for beginner grower it will cause problems later it needs to be altered to grow cannabis well. Lime should be added to the soil to keep the ph from swinging to much it can also burn seedlings but its for sure not the worst thing you can buy. I use mg soil reused mg soil I bake it and then freeze it solid for when I'm ready to use it that way it doesn't burn my seedlings for clones I hope this helps. If its fresh mg soil easy on the watering and don't add any nutes for awhile, some lime right before flowering would help buffer ph lowes or home depot should carry it make sure it's garden lime sometimes called dolomite lime. I hope this helps man message me if you need anything