2 tsp of murphys oil soap per 500ml spray bottle. Spray out of direct sunlight then I like to rinse of 1/2 hour later just to be sure. The oil in murphys helps to kill the bugs.
I used pro mix potting and seeding mix last year and bought the same this year. There are tons of big pieces of wood in and and I wondered if I missed it last year or what? Some pieces were like driftwood.
Don't worry bro I dropped my seedlings earlier in the season and thought they were done and have never looked better. You'll be making us jelous at seasons end.........
Don't spray in direct sun and I alway rinse off after 1/2 hour or so just in case. I use 2 tsp per 500ml water. Get bottoms of leaves well and spray stem too. I read use soft water too, I guess the minerals bond to the oil making it less effective.