Biological filtration is the most important type of filtration in your aquatic system, it doesn’t matter if you’re removing the small particulates if you don’t have enough surface area to grow enough bacteria to handle the ammonia production from all the fish. Luckily biological filtration is very simple, you simply need a high surface area item and you need to put it where water is flowing. #fish #goldfish #aquarium #ranchu | Luke’s Goldies