If I understand correctly, you are bringing inside some dirt from outside to start seeds? I personally would never do that because you are likely to bring in insects/larvae and all kinds of nasty pathogens. Even if they are going outdoors eventually it is better to put healthy starts out than bring outdoors in to start them. I did that my very first ever grow and dealt with all kinds of issues as a result. Bugs tend to want to stick around when they find that comfy a spot.