feeding frozen foods

I am in love with Dumbo Bettas and I am wondering if the dark looking pouch means I am overfeeding the off-white babies I recently bought. Also, I just started feeding them frozen food in the morning.

I'm wondering how some of you give frozen foods to your fish. Over the past years I've only had goldfish to give it to, and there were no problems because they gobbled it up before it sank any more than an inch or so. But I am finding it tricky to feed this stuff to tropicals. Mainly because the...