Are Filters Essential for Fish in an Aquarium?

A bowl holding a single goldfish is a popular trope you see in many Hollywood film and television productions. Many of these cinematic bowls feature nothing else but clear water and the fish. They lack substrate, plants, aeration systems, decorations, filters, and other essential fish tank supplies. What you don’t get to see is that these fishbowls are mostly props. The photogenic goldfish are temporarily taken from healthy aquariums equipped with filters and aeration systems. Once the scene wraps up, the fish are returned to their habitats.

Bare fishbowls in movies don’t require special effects or post-editing to remove filters. Goldfish are hardy species that can survive without a filter, but they can live longer and healthier lives with one. If anything, an ecosystem will be healthier, closer to a natural habitat, and more efficient with filters.

What Filters Do

The three main functions of aquarium filters are:

• Harboring nitrifying bacteria and other microorganisms that complement the nitrogen cycle—in other words, they’re part of a biological filtration system that keeps the fish alive
• Removing toxins that can be harmful to plants and fish
• Complementing the aeration system by providing surface agitation, which in turn helps with mechanical oxygenation of water in the tank

As you can see from the reasons listed herein, keeping a tank without a filter doesn’t make sense.

How Aquarium Filters Work

The two components of filters—the chamber and the media—are converted into a home for Nitrobacter as the water flows through. The small pellets attract bacterial colonies that seek nourishment from fish waste. Combined with carbon dioxide, fish excrement will result in ammonia, a chemical substance that’s deadly for fish. Fortunately, Nitrobacter feeds on ammonia and converts it into nitrates, which fish can live with in small amounts. In the absence of filters, the algae bloom and high ammonia levels will affect water quality and negatively impact the breathing process of your aquarium life. High ammonia burns the gills of fish and prevents them from getting the oxygen they need to survive.

Fish that Can Survive without Filters

Siamese fighting fish (betta fish) are some of the freshwater species that can be kept in fish bowls without filters for a short time, but you still shouldn’t keep your fish like this. Most fish keepers who start out with fish bowls quickly tire of frequent cleaning and water changes. An aerated and filtered tank complete with plants, substrate, rocks, driftwood, and UV lighting is far more enjoyable because it’s a sustainable ecosystem.

If you need high-quality aquarium or pond filters to ensure your fish remain healthy and happy, you can find just what you need at Aquatic Warehouse, as well as a great deal of other necessary supplies for fish keeping. Stop by our store in Kearny Mesa, check out what we have to offer on our website, or give us a call with any questions at 858-467-9297.