Thanks everyone. Unfortunately things have gone down hill. My male Reidi has succumbed to a bacterial infection and I've been forced to put him down.
Ray, if I understand your question, the babies chances being raised with the adults are not so good. They need constant food supplies so trying to get enough food to them in a large tank could be a problem. Also in my experience they aren't very strong so really it is best to sperate them into a small barebottom tank with a sponge filter or air stone. This eliminates the chances of them being sucked into the power equipment. And lastly, there is always the chance that the adult horses will eat the young.