The frequency of feeding your ornamental fish has an impact on the quality of the aquarium water. Water gets dirty quickly if fed in large quantities several times a day. It is best to feed your fish 2 times a day. Aquarium Tips: Feeding fish using cheap and substandard products has a serious impact on aquarium water quality. The water quickly turns red and smells fishy because ornamental fish food products consist of low qualities of mosquito larvae, brine shrimp and others. Give fish food that is high quality and has lots of nutrients and vitamins. Based on our experience as an aquarist, we will change the aquarium water by 50% periodically every month or 30% periodically every 2 weeks. Use a fish waste suction device (aquarium siphon vacuum) in addition to cleaning the filter sponge. Replace with a new filter sponge if torn or worn.