Feeding Issue

My male bristlenose has finally hatched a batch of eggs on the third breeding attempt!

They are still in the cave, which is actually a rock with holes in it (trust him to chose something that wasn't meant for him), and the babies are under it, he has pushed all the sand out of the way so the rock is balancing and the babies are either on the bottom of the rock or on the bottom of the tank. The trouble is I can't see if they have lost their sacs, so I don't know whether to feed them. If they try and come out from the rock he moves them back in, am I right in thinking that means they are too little to leave? I don't know when they hatched, we first noticed them on Monday, but I can't remember when they laid the eggs.

I've put some extra algae wafers in there today outside the rock, but the female is taking advantage! Am I just worrying too much about them?

Nip down to the local shops and grab a cucumber. Slice of a thickish disk, stick a stainless steel fork through it and drop it in. after 24hrs remove and repeat. The babies will begin to feed on it when they are ready and it wont foul the water like over feeding with algae wafers will. Much better food for the bristlenose anyway

i think when the fry start to ove out of the cave and u can see they have no sac.