Just about no betta would go near one of those food blocks, so it's likely to do no more than pollute the water and possibly kill your fish. Plus, they have the nutritional value of chalk. Probably taste like it too.
I suggest you just leave your fish be, no food unless someone will be doing a water change to reduce waste. I have left my bettas a week without food, because I didn't trust the person feeding my cat to do water changes for me. When I came back, the bettas were happy as heck to see me, and their bottle of pellets. They just got a little hungry.
Point is, you'll be better off not feeding the girl if she stays in a 1g. The others could do with one or two light feedings though.
And, JKfish, that poor betta. We had a classroom betta when I was in primary school. His name was Bluey. He jumped out of his tank during the weekend. :( I think this was about 6 years ago though, before I started keeping fish.
Last edited by Venom; 06-05-2010 at 07:59 AM.