At Swell we have a wealth of fish food suitable for fish in a cold water tank. Flakes, pellets and granules can all help to keep your fish happy and healthy which in turn enhances their colours.
Different fish have different needs, surface feeders for example will prefer flakes and floating pellets while mid water feeders like granules or slow sinking foods. Bottom feeders such as catfish will prefer food that sinks quickly, so that they can pick it up from the gravel. Remember that any food left uneaten at the bottom of the aquarium can pollute your tank, so avoid over feeding and try to take out any leftovers.
It can be a good idea to use a gravel cleaner to remove any waste and leftover food from the substrate.