Cleaning the aquarium FAQ

Why do people choose to clean their aquariums?

There are three main reasons why people clean their fish tanks. First, the tank may start to smell. This odor can come from different sources, such as unfiltered waste, leftover food settling at the bottom, or even dead fish. To maintain a healthy environment in the tank, it’s crucial to have a sufficiently powerful filtration system. However, still water can naturally develop an odor, and some aquariums without filters, but with many plants, can maintain stable conditions through the plants' natural processes.

Another reason to clean the aquarium is when it becomes overgrown with algae.

Keep in mind that algae typically thrive in aquariums with insufficient plants, inadequate nitrification bacteria, or excessive lighting. To address this, you might consider adding algae-eating fish, such as plecos or corys. Algae is a natural part of aquariums and can help maintain water conditions and chemistry. Fish waste settles at the bottom of the tank, where it becomes part of the substrate. If the substrate is of high quality, it transforms harmful waste into nitrates, which are primarily composed of oxygen. With enough aquatic plants, algae growth will be minimized since the plants will absorb the fish waste. However, if your tank has very bright lighting, it can encourage algae growth, as light promotes the growth of both plants and algae.

The third common reason for cleaning a tank is when the water turns brown or yellow

These colors are often caused by driftwood, roots, and other decorations in the tank. There’s no need to clean the water just because it changes color, as this is a natural occurrence. Many biotopes around the world don’t have crystal-clear water. For instance, rivers and streams in South American rainforests often have a brown, yellow, or black tint due to the presence of trees and organic matter. Driftwood, while it can darken the water, is beneficial for fish like plecos and corys. Adding roots or driftwood to your tank can create new hiding spots for fish, which is especially important for species that are active at night or prefer dim environments. Ancistrus species, for example, need shelters for their well-being, breeding, and play. While plastic decorations can be attractive, they can’t replicate the benefits of a more natural setup.

People typically clean their tanks every 2 to 4 weeks. Personally, I don’t clean my tanks; I only add water to replace what has evaporated. I chose this approach years ago because I noticed that the cleaning process stressed my fish. The stress came from trimming plants and cleaning the filter. Imagine yourself and your family as fish, and your home as an aquarium. How would you feel if a "higher power" showed up at your house every two weeks without warning? It would likely be unsettling. While I wouldn’t mind someone tidying up my home, I understand how such frequent intrusions could be distressing for fish.

Nitrification bacteria are essential for a reason; they are crucial for all aquariums

You shouldn’t harm these bacteria, as they play a vital role in maintaining water clarity by breaking down waste. It typically takes about two months for them to effectively filter the water. When combined with a good filter, they help ensure stable conditions and prevent disease. All my fish remain healthy and thrive. To support this process in the first two to three months of setting up a new tank, consider changing 10% of the water every two weeks.

When setting up a new aquarium, it's important to focus on using clean decorations, tank parts, and the tank itself. Everything you add to the tank should be free of bacterial organisms and potentially harmful items, such as sharp shells. To ensure this, boil all new objects before placing them in the tank. Additionally, if you suspect any disease, thoroughly clean the entire tank to prevent losing your fish and plants.

As you can see, there’s often no need to clean tanks on a regular basis. Unlike cichlid aquariums, community tropical aquariums typically require less frequent cleaning. Cichlid tanks, which have few plants, take longer for nitrification bacteria to establish a substantial colony. Therefore, it’s recommended to change 10% to 20% of the water every two weeks. In nature, there are lakes without plants or filtration where fish still thrive. This suggests that many tanks could potentially exist without regular cleaning, which might sometimes be more harmful than beneficial. However, smaller aquariums do need more frequent cleaning due to less stable ecosystems compared to larger tanks. In my view, larger tanks tend to present fewer problems.