When would be the best time to pot them in the 20L...

Hey, just leave them out. the temperature is good to go know. even at night. And, let them go dry. lift the pot, when its easy like no water is inside, water them again. makes the roots grow better, faster, and you want get problems with to wet and shit. ;) go out, get some wilg. Take just the young, green, flexible steams. Cut them small, like 1 cm pieces. Put it in a bowl, but please, no plastic. Than cook some water, and rinse it over the wilg into the pot, and let it stay for 36 hours. than take the water, the rest you can put on the compost or put it into the nature. Take some water, add the same amount of wilgwater and give it to your babys !!! There is a grow hormone iside the water that makes the roots grow faster !!!! just try it !