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Aquaponics: The Basics of Fish Tank Hydroponics

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Zach's writing ranges from matters of gardening, cooking, aquariums, and fish to more niche topics like coin collecting.


Let's face it, beyond the memories and good times observing your aquarium fish, the hobby of fish-keeping is much more taking than it is giving. Functional and healthy aquariums require routine maintenance from the fish-keeper and a handful of costly necessities to keep the water parameters in check.

If you're already dedicated to the work and costs associated with running an aquarium, this is a good time to add a few modifications to turn your tank into a veggie-producing machine! That's right, vegetables! The technique is called aquaponics, and the design behind it couldn't be easier. In this article, learn how to convert an average aquarium into a small aquaponics farm that really gives back.

What Is Aquaponics?

Aquaponics can best be described as an alternative agricultural means for producing fruit and vegetable crops by incorporating aspects of both hydroponics and fish-keeping. The methods used among commercial and large-scale aquaponic farms vary a bit, so for the sake of the small aquaponic farmer, plants are normally grown above the aquarium in a separate container of an inert growing medium.

Utilizing a small water pump located in the aquarium, water is then pumped to the growing plants and allowed to drain back into the tank. Growing plants that are able to uptake nutrients leftover from fish respiration and bacteria present in the growing medium will continue to filter and clean the returning water. The plants and growing medium can be looked at as one large filtration unit.

Ten-gallon aquaponic setup

Ten-gallon aquaponic setup

The Basic Necessities

  • Aquarium: Any size aquarium may be adapted for use in an aquaponic system. Note that larger aquariums tend to provide more stable water conditions and should be highly considered by those new to fish keeping.
  • Air pump: Since most aquaponic aquariums can be run without the use of a mechanical hang on the back filter, an air pump must be used to provide sufficient oxygen to the water column.
  • Heater: An aquarium heater is not absolutely necessary, especially since aquaponic aquariums should be kept slightly cooler than tropical aquariums. If your tank is cooler than 60–70°F, consider investing in a heater to get your tank into range.
  • Water pump: An adequate submersible water pump will be at the heart of your aquaponic farm. Since each system is different, make sure that you'll have the right pump for your specific setup.
  • Growing container: As long as it's watertight and non-toxic, just about anything can be used as a container to hold your growing medium and plants. Dark-colored plastic storage bins are often a prime choice.
  • Growing medium: The roots of growing plants will need something to grab hold of during their stay in your aquaponic system. Only inert mediums should be used in aquaponic systems. One or a combination of Rockwool, Hydroton, gravel, or any other grow stones may be used.
  • Grow light: The lighting system that you choose to use could be the most expensive aspect of your indoor aquaponic garden. Then again, it could be free! If a well-lit and south-facing window is available, natural sunlight can be used to power your garden. If natural light cannot be utilized, fluorescent or similar lighting of 100 watts or more should be considered.
  • Plumbing and tubing: The plumbing and fittings needed for every aquaponic system will differ. It's essential to purchase the proper fittings for the job so that your system runs smoothly and remains water tight.
  • Fish tank stand: Be sure that your stand will be able to support the weight of the tank, growing medium, and additional equipment!
Drip aquaponics

Drip aquaponics

Choosing Your Indoor Aquaponic Setup

Many different hydroponic methods can be incorporated into your aquaponic system, allowing you to choose what will best suit your application. If you're unfamiliar with hydroponic techniques, start with researching flood and drain, deep water culture, nutrient film technique, and drip hydroponics, as these are all viable options in conjunction with aquaponics.

For my experimental ten-gallon aquaponic setup, I've chosen to go for a drip system. From the aquarium, water is pumped through a delivery tube where the water is allowed to drip at the base of each plant. Water then filters through a layer of Growstones and back into the aquarium via a drain tube.

Cycled ten-gallon aquaponic aquarium

Cycled ten-gallon aquaponic aquarium

Cycle Your Aquarium

Now that you've got the details of your aquaponic system worked out, the last stage is to ensure that your aquarium is properly cycled. New aquariums must be cycled to ensure the growth and development of beneficial bacterial colonies. These all-important organisms are the fundamental base of the nitrogen cycle and are how fish byproducts are converted into nutrients for root uptake.

If you've never cycled an aquarium before, please reference this guide from Aquariums one month and older with established aquatic life are already cycled and need not be recycled before adapting for aquaponic use.

The Key to Aquaponics: Have Fun!

Although the basics of small aquaponics tend to be the most time-consuming aspects, the payoff will be well worth the effort! Hopefully, this article has given you some ideas as to what equipment and practices will be needed to set up your own aquarium aquaponics.

While it might be a bit overwhelming at first, the key to aquaponics is to have fun and always experiment with new techniques! Just remember, your fish tank should be working for you, not you for it! Please feel free to leave any questions or comments, as I would love to hear your feedback! Thanks for reading.

More About Aquaponics

  • Aquaponic Build: The Functioning System
    With the basics behind us, it's now time for the functioning aquaponics setup! In this article, we'll cover the rest of what's needed to bring your aquaponic build to life.
  • Practical Aquaponics: Maintaining the System
    To keep your mini aquaponics setup running smoothly, you'll need to learn the basics of dechlorination, water changes, and other essential practices!
  • How to Make Your Own Fish Food
    Making fish food couldn't be easier! It's time to free yourself of commercial fish food flakes and start creating your own natural alternative. Homemade fish food is not far away!