Cherry Barbs off their food

I've got six Cherry Barbs in a 10 gallon tank with 4 SAEs, three Otos and a
few snails. I know it's over stocked, but the SAEs will be moving on one
day. I normally feed the Barbs freeze dried Blood worms and let the rest of
the crew feed off the Algae. I occasionally feed the clean up crew some
Algae wafers, although I think it's affecting their efforts. But the Barbs
have been less than thrilled with their food lately.

My first thought was that the Nitrates might be getting too high, as I only
change the water every 10 days or so. But they tested at less than 5 ppm
after tonight's water change. So I guess the little buggers are getting
bored of their food? I did feed them a few frozen Blood Worms last week,
that I give to the fish in the large tank on weekends. No one seems to be
suffering, so I guess they're expecting the good stuff now! Although I'm a
little surprised by this behavior in barbs.