Do Goldfish Have to Have a Filter in Their Tank?

Sponge System

• The sponge system utilizes a large sponge that helps collects waste and other harmful particles in the tank. It's either attached to a power head or air pump and draws the water gently toward to sponge to remove harmful particles. These are ideal for larger tanks because the sponge itself can take up a significant amount of room depending on the size you choose to purchase.

Under Gravel System

• The under gravel system is placed at the bottom of the fish bowl, with gravel covering over top. This makes it much more ideal for a smaller goldfish bowl than the sponge. To set up, the filter is first rinsed with water and placed at the bottom of the bowl. Then, the uplift tube is inserted into the corresponding opening on the filter plate. The filter plate is then covered with gravel and connected via an air pump to the filter plate. The air pump draws the water toward the filter and removes unwanted particles.

Cleaning the Bowl

• Aside from filtering the water, new water needs to be placed in the bowl at least once a week. After removing half the water in the fish bowl, pour the same amount of distilled or filtered water in a separate bowl on the counter. Allow the water to sit out for at least a half-hour so it becomes the same temperature as the water in the bowl. Finally, gently pour the new water into the fish bowl.

  Once a month, pour one-quarter of the fish bowl water into a separate container. Using a fish net, remove the fish and place them in the same container with the old water. Fill the fish bowl three-quarters full with fresh spring or distilled water. Allow the water to sit in the fish bowl for about a half-hour until it's room temperature, then return the fish to the bowl using the net. Finally, pour the water sitting in the separate container back in the bowl.

Feeding

• Goldfish are omnivorous, meaning they'll eat anything...so the risk of overfeeding them is great. The excess waste poses two risks to the water quality. The first is if the fish consume excess food, they'll produce excess waste, which impairs the water quality. The second is that excess food that's not consumed also deteriorates, which also contributes to poor water quality. Feed the goldfish once a day in accordance with the amount recommended on the fish food packaging.