A fish tank is a lot different than the natural environment where fish would normally live. Fish are used to having thousands of gallons to swim in. In our system they only have 20 gallons of water to swim in!
The small amount of water makes it easier for bad bacteria and other toxins to overtake the system and cause the fish to get sick or even die.
This is why cycling is so important. Cycling the water through a filter helps build up the good bacteria that are needed to break down the fish waste and reduce ammonia build up in the system.
Using plants to filter the water is a lot more like nature. The plants use the ammonia build up for food while keeping the water clean for the fish! After March break we will add fish to the system.