should transplant them into a pot of perlite, itll help all those nute balls get out of there hopefully with a flush or two, if the soil washes out just add more topsoil or perlite. dont feed until they stop getting burned, watch the leaves really close though. adding perlite to this will help them wick out from overwatering, you can also poke holes in your soil away from the taproot and help it not go root bound until you get some perlite or a more aerated medium, MG tends to soak up way too much moisture. fill the holes you poke into the top soil or sides of the pot(making extra holes always helps them wick out too) with perlite. after they wick out completely, the holes should collapse on themselves or look dry or a lighter shade of brown.yeah, it's mg soil, are they ok like that though?, not introducing nutes for another two weeks at least. and def not overwatering, but i'll def make sure they're completely dryed out and pick the pots up. Are they ok otherwise?
-http://420deku.blogspot.com/2011/01/how-to-fim.html"I usually FIM plants when they are between 1-2ft tall and it should be done at least 2 weeks before turning to 12/12 to maximise the growth potential of the new shoots and maximise the benefits of using this method."