When feeding your fish, you don’t always have to use an entire cube of frozen food. Just use whatever the fish will eat over a very short period of time, then store the rest in the refrigerator. Then, if you feel the need to feed again, you don’t have to wait for the food to thaw out again, just set it out for a few minutes or even feed the fish cold food. If you feed the entire cube of food to a small group of fish, the uneaten food will eventually settle in the dead spots of your aquarium and decay, releasing algae-fueling nutrients into the tank. Don’t always rely on the clean-up crew to handle the excess food either, as they can also get full and stop eating the leftovers.