Best Flow Rate for Planted Aquarium

The efficiency of your aquarium’s filter depends on the amount of water passing through it.

This means that the water in your aquarium will remain cleaner for longer, which is beneficial for the fish and other aquatic life that lives there.

Your aquarium’s water has to be filtered and pumped around four to five times each hour.

Even in ideal conditions, the performance of pumps and filters can decelerate significantly.

For this reason, it is suggested that the water capacity in larger aquariums be increased by a factor of 10.

Although this may seem like a lot, it will allow the plants to sway softly, which is the ideal condition you’re aiming for.

This article explains and recommends the best flow rate for the planted aquarium.

How Much Flow Should a Freshwater Tank Have?

Without a continuous flow of water, it will be very challenging to maintain a clean tank.

It is not possible for filters to treat water on their own.

They require a consistent flow in order to move the water in your tank through the filtering system.

In this way, your water will maintain its high quality, and the environment in the tank will be ideal for the growth of your plants.

The flow assists your plants to wash off any particles that have accumulated on the leaves of a plant and removing them from the surface of the plant.

Large fish require greater flow rates and may be more powerheads to get as much fish debris into the filter for removal.

Reef tanks need more flow to circulate water throughout.

A freshwater tank should filter at least four times its water capacity. So, if you have a 30 gallon tank, then it should filter and pump to handle about 120 gallons per hour (GPH) of water flow.

Betta, baby, and small fish aquariums need modest flow.

Plants need CO2, thus reducing surface agitation helps.

Most plants cannot stand in a strong flow stream.

However, larger tanks can handle more, depending upon the amount of plants in them.

How to Calculate Flow Rate in Aquarium?

Having a steady flow of water moving from the aquarium to the filter is crucial.

The filtration system is responsible for maintaining the aquarium water quality.

But if the current is too strong, it might be distressing for the fish.

If a fish had to swim against strong currents around the clock, it would get tired of the endeavor.

On the contrary, a low flow will reduce water movement and may not allow for adequate filtering.

Flow Rate Calculation

Testing your pumps’ flow rate under typical working settings is necessary.

To perform this, you will need a bucket with 3 to 5 gallons of water, all the pipes and equipment, and the pump in its outlet.

After setting up the pump and piping, pump water out of the bucket and measure how long it takes to move a particular amount.

If the pump pushed 3 gallons of water in 30 seconds, its flow rate was 360 GPH. (GPH = Gallons per minute x 60)

Calculate your aquarium’s turnover rate by knowing your pump’s gallons per hour.

For instance, if your pump flows 280 GPH and your aquarium holds 48 gallons, then divide 280 by 48 to obtain your aquarium’s turnover rate, which in this case is 5.83.

It is important to take into consideration the volume of water that is contained within your aquarium while caring for planted tanks as well as tanks in general.

You will be able to make an exact calculation of the water flow that is required for the setup of your tank using this method.

The size of the pump needed to accomplish a specific flow rate varies between interior and exterior pumps.

Internal submersible pumps need less power since they do not have to push water uphill.

External pumps are used in larger aquariums since they are more powerful and may power many systems.

A pump with a flow rate of at least 275 GPH is required for a freshwater aquarium that is 55 gallons in capacity.

In contrast, a large freshwater tank of 125 gallons will need to employ a pump that has a flow rate of at least 625 GPH in order to function properly.

Do Aquarium Plants Need Water Flow?

A healthy flow rate assists your plants in a wide range of ways, including their overall health.

For example, your plant must have some means through which it may obtain nutrition.

When there is just the proper flow of movement, carbon dioxide and nutrients may be dispersed throughout the water.

Some plants may lack nutrients and CO2 if the flow is inadequate.

Avoid dead areas in your tank produced by pebbles and wood.

Dead plants lack nourishment and water. Black Beard Algae (BBA) grows in these dead spaces.

Even while photosynthesis feeds your plants, the correct water flow will keep them healthy and growing.

That’s why it’s important to monitor and regulate water pressure.

In any case, the water pressure shouldn’t be too high.

A sufficient flow rate allows tank water to pass through filters. It should not be too high to wilt your plants.

Plants are sensitive to water movement and too much movement might be detrimental.

Excessive water movement and turbulence might damage or even uproot your plant.


Having the right flow rate for your planted aquarium is essential for the health of the fish and other aquatic life.

The best flow rate for a planted aquarium is determined by the size of the aquarium, the type of filter system, and the type of plants and aquatic life living in the tank.

For a smaller tank, we prefer a slower flow rate for the growth of plants and the health of fish and other aquatic life.

It helps maintain a cleaner environment and supports the growth of your plants.

By understanding and managing the flow rate of your aquarium, you are taking a step towards creating a thriving aquatic ecosystem within your tank.

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