How Do I Keep My Aquaponic Tank Clean?

Maintaining a clean aquaponics tank requires consistent monitoring of the system. This means you should check for any irregularity in your system and elements that should not be there in the first place.

What causes my aquaponic tank to get dirty?

Too many algae

Algae is a plant life that consists of several different kinds of plant-like creatures. Algae come in various colors and textures, including slimy, bubbling, stringy, and even furious. However, all algae have the same demands: light, air, and nutrients. If the algae have all of these, they can grow quite quickly.

When there is an overgrowth of algae in your fish tanks, it is called an algal bloom. An algal bloom is a concern in any aquaponics tank because it disrupts the natural ecosystem developing in your system. Algal bloom presents many challenges to any aquaponics grower, but for the sake of our topic, it makes your system filthy and unattractive.

Animal droppings

These are common when you do not provide coverings for your aquaponics system. Bird poops are good examples of animal excrements that may end up in your fish tanks. The manure of other warm-blooded animals may not only make your tanks contaminated but also introduce pathogens such as E. coli.

Malfunctioning equipment

When the filtration system of your aquaponics setup breaks down, the water that runs across it will be unfiltered. Consequently, the wastes of the fish will remain, leading to murky fish enclosures.

Uneaten fish food

Whether you assess your fish's dietary needs, choose the highest-quality fish food, or stick to a strict feeding schedule, there will always be some leftovers in the fish tank. Flakes or pellets may still float or sink in the fish tank regardless of the fish food.

The leftovers gradually ferment or degrade, causing the fish tank's water quality to deteriorate. When dissolved in water, carbon dioxide generates carbonic acid, one of the breakdown products. As a result, the acid changes the pH of the water in the fish tank, making it unsuitable for fish life.

How should I clean my aquaponics tank?

Aquaponics is a system that simulates a natural ecosystem by filtering, purifying, and recycling waste-rich water. As a result, you won't even need to replace the water in your fish tank because it's a self-cleaning system. However, there may be times when you need to change the water in your aquaponics system because the water is already filthy.

Below are the steps on how you can change the water in your fish tanks:

  1. Prepare all the necessary materials and equipment. Here are some of them: A siphon/gravel vacuum, a thermometer, a small tank or a dedicated 5-gallon (22.73 L) bucket, and a testing kit.
  2. Prepare the replacement water by testing it first to confirm that all parameters are within acceptable limits. Rainwater is the best sort of water to use. If you only have access to tap water, let it sit overnight to let the chlorine evaporate, or apply a water conditioner if it contains other chemicals.
  3. In addition to the parameters, use a thermometer to check the water temperature to see if it's suitable for the fish breed(s) in your tank.
  4. Remove feces and other organic debris that has settled at the bottom of the fish tank with a siphon/gravel vacuum. Remove roughly 15-25 percent of the entire volume of the tank while siphoning. However, be gentle and avoid removing extra water, as this will destroy your aquaponics system's bacterial colony (biofilter).
  5. Replace the withdrawn water with the freshly prepared water. You should also test it again to ensure that all parameters are at their best.

How do I keep my aquaponics tank clean?

Control algae growth

As mentioned above, an algal bloom is something aquaponics growers do not want to experience. Thus, you must take considerable steps for this not to happen. Here are some of them:

  1. Hand-removal: This is the simplest and easiest method of controlling algae growth. However, this can only be considered a band-aid solution since it is short-lived and labor-intensive.
  2. Mechanical filtration: The mechanical filters are crucial components of your aquaponics system. One of their functions is to keep algae from invading or spreading in fish tanks. Examples of mechanical filters are screens, filters, and settlement tanks. These devices even remove spores from the water as well as mature algae.
  3. Covering the water tank: Algae grow in fish tanks with light exposure, most especially sunlight. Since this is the case, you can hinder their rapid growth by covering the tank with an opaque substance. Furthermore, if your fish tank is movable, you can move it under a shade to deprive algae of light.
  4. Using humic acid: Humic acid successfully removes algae from fish tanks and is an excellent additive to soils to boost plant production. Because the acid darkens the water, algae can't get enough sunlight.
  5. Utilizing a UV filtration tube: This equipment is a UV lamp that sterilizes the water in a fish tank by emitting UV rays. As a result, the filter tube removes algal spores from the tank and prevents algae reproduction and spread in your aquaponics system.

Avoid overfeeding of fish.

When fish are overfed, they produce more body wastes which in turn contaminate your tanks. Therefore, it is vital to avoid giving your fish too much food.

Because waste and uneaten food can decay inside the system, they are incredibly toxic to aquatic species. Food that has rotted can spread disease and deplete dissolved oxygen. Remember to feed the animals every day, but take away any uneaten food after 30 minutes and modify the portion for the next day.

Remove fish food leftovers.

When the temperature is warmer (during the summer), and the fish are actively growing, they will quickly feed. If you detect a change in their appetite, it may indicate that the water quality is terrible or that the fish are sick. One cause will be the fish food leftovers if the former is the reason.

To remove uneaten fish food, do the following simple steps:

  1. Using a fine mesh fishnet, scoop the floating meal remains (fish flakes).
  2. Using a siphon or gravel vacuum, suck the uneaten food from the bottom of the fish tank — it's an easy and quick way to clean a fish tank.

Conduct routine maintenance of your components or equipment.

The purpose of this practice is to evaluate the functionality of your filtration system. A faulty filtration system will adversely affect the cleanliness of your fish tanks.

Consider cleaning your filters, clarifiers, and biofilters once a month to avoid blockage. When something plugs the pipes in your system, the performance of your filters may suffer, and the water will be polluted and filthy eventually.


A fish tank is one essential part of any aquaponics system. A fish tank serves as a nutrient reservoir and housing the fish, as it collects fish waste and nutrient-rich water before being pushed to the growth beds. As a result, keeping the fish tank clean and good working status is always advisable.

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