Is It a Good Idea to Turn Off an Aquarium Filter at Night?

Aeration and filtration systems for aquariums, which are some of the most crucial freshwater and saltwater aquarium supplies, are meant to operate around the clock. Some of these systems separate the filter element from the pump, but the majority are single units that won’t filtrate efficiently unless the air pump is running. Either way, the system should only be turned off for a short time in certain occasions, like maintenance, but never at night. Unlike tank lighting systems that are turned off at night to provide fish with circadian patterns, filters need to stay on for the purpose of keeping up dissolved oxygen volumes necessary for aquarium species and critical biological bacteria.

Understanding Aquarium Filtration

Without constant filtration, the nitrogen cycle necessary to support a healthy aquatic ecosystem would be disrupted. The easiest way to understand aquarium filtration is to compare it to the residential garbage collection and toilet plumbing processes. Imagine what would happen if human waste piled up in our homes without proper disposal. This would be equivalent to turning off filtration and allowing fish excrement, food fragments, detached scales, and other biological waste to accumulate. You may not notice this accumulation in the beginning, but once the water starts turning murky, dangerous ammonia levels will rise.

Oxygen Levels in Aquascapes

Tanks that contain a good amount of plant life tend to be healthier, but this doesn’t mean they’re any safer without constant filtration. In fact, when plants aren’t actively engaged in photosynthesis, they (along with filtration nitrifying bacteria) consume more dissolved oxygen, thus depriving fish and invertebrates from this precious element at night. During the hours aquarium lights are turned off, filtration must continue, particularly if the aquarium has plants.

Quiet Filtration Systems

The motivation for turning off pumps and filters at night is often related to noise levels. In general, air pumps tend to be noisier whether they’re integrated with the filtration system or operate separately. In the case of filters that run independently from air pumps, the latter could (but best not to) be turned off overnight, but you’ll still have an aquarium that isn’t being optimally aerated and filtered 25 percent of the time. Aquarium systems are never completely silent. However, some are quieter than others, especially those that separate aeration from filtration.

Measuring Dissolved Oxygen Levels

Saltwater fish keepers rarely think about turning off their filters even for an hour. This is because maintaining adequate water temperature and oxygen levels is a bit more involved compared to freshwater tanks. Should you decide to turn off your filters for a few hours, monitoring dissolved oxygen levels with a sensor is highly recommended. Some sensors are equipped with alarm systems that can alert you when the dissolved oxygen volume has reached a certain level. If you notice the larger fish in your aquarium will only swim near the surface, this is a sign they’re gasping for oxygen, which could indicate a problem with your filtration system.

In addition to aeration and filtration, there are several other things to consider when it comes to caring for an aquarium. Whatever aquarium supplies you need, whether it’s an aquarium dosing pump, LED lighting, or beneficial bacteria, you can find it at Aquatic Warehouse. Call us today at 858-467-9297 if you have any questions.