You'll have to lose the ugf. Remember those pits they were digging? The minute a plate is even partialy uncovered the ugf fails to function since all the water gets sucked through the uncovered part of the plate. I would go get the largest Aquaclear you can buy (Africans are messy,and the tanks need to be slightly over stocked for the overcrowding plan to work). Actually I would get two smaller aquaclears since 30g tanks are so long. Fill a filterbag with gravel and place it on the bottom of the media basket so that it is in direct contact with the sponge. Let this run for at least a week and the filter should be cycled. Your gravel bed will continue to act as a biofilter, just not as efficiently since water is not running through it, just over it. Since you're dealing with fry in an established 30g the bioload will be small and you should not have any trouble.
