How Long Can a Planted Tank Go Without a Filter?

The filter is vital for sustaining the overall health of your aquarium. It will remove contaminants from the water in your planted tank, such as uneaten and rotting food, waste from fish, and dead plant stuff. The filter is a strong workhorse that has to function 24/7.

A filter is necessary for keeping excellent water quality since it eliminates hazardous chemicals from the tank water and aids in maintaining optimum oxygen levels for your fish and shrimp. There could be serious consequences from shutting it off for long periods of time, leading to a contaminated ecosystem. Without a filter, a planted tank may thrive, but it’s difficult. Before removing the filter, make sure your live plants can manage the biochemical load in your tank and maintain good biological filtration.

This article explores the importance of a filter in a planted tank and the consequences of using it intermittently.

High Tech vs. Low Tech Aquarium

Aqua enthusiasts differentiate low-tech aquariums from high-tech aquariums by providing extras like light, carbon dioxide, and plant food, however, there is no universally accepted definition for either. There are benefits and drawbacks to each, as well as varied costs and maintenance needs.

The fundamental difference between the two aquarium types is the artificially injected CO2. The natural amounts of carbon dioxide (CO2) that are already present in your tap water and the gas exchange that takes place at the water’s surface are what low-tech tanks rely on to produce CO2.

In order for plants to achieve healthy growth, they need certain amounts of light, carbon dioxide, and macronutrients. Algae may bloom with uneven concentrations of these three components.

Most high-tech aquariums require a CO2 system and strong lighting. Low-tech tanks simply need low or medium light intensities, no CO2, and a few macronutrients.

Several varieties of plants, such as Rotala macrandra and Hemianthus callitrichoides (dwarf baby tears), need more CO2 and light than is generally provided in an aquarium. Without supplemental CO2 and light, these plants would struggle to survive in low-tech environments.

Another prominent difference is high-tech tanks require more upkeep and resource use, hence they cost more. Avoiding unintended consequences requires more detail-oriented attention.

Which aquarium setup is better for you depends on the plants you want to cultivate and how much time you are ready to put in. The best way to learn the ropes and get acquainted with the principles of planted tanks is by starting with a low-tech installation if you’re new to planted tanks.

Do Planted Tanks Need a Filter?

Aquarium plants can aid in removing contaminants from the water and convert carbon dioxide into oxygen. This may sound similar to how a filter functions. Yes, it is more or less the same, but the difference is how much water a plant or filter can filtrate.

The amount of plants in the aquarium, and the number and type of fish influence the efficacy of the filtration system. If your tank size is big with many fish, then a few plants would be incapable of conducting effective filtration.

You can’t just pitch a few plants into a freshwater aquarium and hope they’ll do the job of filtering the water. But numerous live plants in a moderate-sized tank may absorb all the waste and carbon dioxide generated by a few fish.

Therefore, the number of aquarium occupants, types of aquarium plants, and the size of the aquarium are important variables in determining whether a filter is necessary for a planted tank.

What Do Plants Do in the Aquarium?

Photosynthesis is the process that live aquarium plants undergo throughout the day in order to grow. It can also process whenever the lights are switched on in your tank. Carbon dioxide from your aquarium’s water, an outcome of your fish’s breathing, helps them achieve this. Then it uses the energy from the light to convert carbon dioxide into oxygen.

Aquatic plants naturally filter the water chemicals. Live plants absorb water contaminants, including ammonia, nitrate, and nitrite. These chemicals are harmful to fish, therefore eliminating them from the aquarium.

Water plants can help control algae blooms by using up the same nutrient supply algae requires. Nevertheless, aquatic plants enhance the aesthetics of your aquarium, in addition to their many benefits.

Maintain a Planted Tank Without a Filter

Turning off your filter for one night probably won’t kill your fish. Those little creatures sure are resilient. But until you give it a try, you won’t know if your planted tank can survive without a filter.

It is possible to keep a flourishing planted tank without a filter. It is referred to as the Walstad method, also known as the all-natural, chemical-free method of maintaining fish.

In the Walstad method, we use soil as the aquarium’s substrate. Then it’s time to grow some plants in it. Aquatic plants provide a source of oxygen for fish. They’re great for cleaning up fish waste, which contains ammonia. The carbon dioxide gas that fish exhale is also useful to plants.

They may use decomposed fish food as fertilizer, providing essential nutrients to promote plant growth. It nourishes the plants regularly, so you won’t need aquarium fertilizers. They may recycle CO2 from the aquarium’s air.

Without natural sunshine, plants will need to rely on artificial illumination. Initially, you may need to change the tank water regularly. Once the tank is fully mature, a water change every three to six months is all that’s needed. This completes the natural filtration in a planted tank.

Fewer plants cannot filter suspended debris, thus it would be wise to use mechanical filtration initially until there are lots of plants. You may remove the filter when your tank has lots of beneficial microorganisms.


Even if you have sufficient live plants in your aquarium, having a filter is really advantageous. One of the key areas in your tank where helpful microbial colonies flourish is the filter. Furthermore, the filter aids in water aeration more effectively. Not just for the fish, but also for the bacteria, oxygen is critical in your tank. They would all perish if it did not exist.


Filtration in the Nature Aquarium | Tropical Fish Hobbyist Magazine (

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