Can I feed rosy red minnows only algae wafers?

I just got 6 rosy red minnows. I also have a pleco in the tank with them. I tried feeding them tetra flakes but they ignored them. I put an algae wafer in for my pleco and they seemed to love it! Could I feed them that once a day instead of feeding them flakes twice a day? Or could I give them two algae wafers a day?