Imagine picking fresh basil while fish swim in a tank below, helping provide the nutrients those plants need to grow. That is what drew me to aquaponics. I have loved keeping fish since I was five or six years old, when I had several ten-gallon aquariums filled with guppies in my bedroom.
Over the years, my fishkeeping adventures grew to include goldfish and even a 100-gallon community aquarium. Then, around 2000 or 2001, I began experimenting with hydroponics, growing plants without soil. When I learned that aquaponics could bring those two interests together, I couldn't wait to see what we could create using equipment we already had.
Of course, keeping fish healthy while growing vegetables and herbs means paying attention to far more than simply pumping water from a fish tank to a plant. That was part of the adventure, and our little 29-gallon experiment had plenty to teach us.
How Aquaponics Combines Fishkeeping and Hydroponics
In hydroponics, I manage the nutrients in the water to feed the plants. In an aquarium, I feed the fish and maintain the filtration that keeps their water safe. Aquaponics brings those jobs together. Fish release ammonia, and beneficial bacteria convert it first into nitrite and then into nitrate, a form of nitrogen that plants can take up. Without a functioning biological filter, fish waste can become dangerous long before the plants have a chance to use the nutrients.
That is why aquaponics is not simply a fish tank with a plant perched on top. The system needs dependable water circulation, dissolved oxygen, an established bacterial population and a balance between the number of fish and the amount of plant growth. Fruiting crops such as tomatoes generally demand more light and nutrients than leafy greens. Fish waste may not supply every plant nutrient in the right proportions, either, so any supplementation must be chosen with the fish's safety in mind.
Aquaponics combines aquaculture, the raising of aquatic animals, with a soil-free plant-growing system. Fish release waste into the water, beneficial bacteria convert that waste into forms plants can use, and the plants take up some of those nutrients as the water circulates. It is a partnership that depends on suitable water conditions, oxygen, filtration and careful stocking rather than a system that takes care of itself.
My own adventure began with a desire to build an aquaponics setup using what we could find and repurpose. I wanted to grow herbs and vegetables while learning to care for fish in the same connected system. That led to experiments with growing containers, pumps, water movement and eventually a 29-gallon aquarium.
Some parts were exciting, others were frustrating, and every stage taught me something I could not have learned simply by reading a set of instructions. Here is how the project began, what I learned along the way and what I would want another gardener to understand before trying it.
Planning Our First Aquaponics Experiment
I was fascinated by aquaponics long before I had the equipment to try it. My first mental picture involved a much larger system, complete with a food-grade tank big enough to hold fish comfortably. The size and cost of that setup made it seem out of reach, especially because I hoped to repurpose equipment rather than buy everything new. The thought of cultivating plants while nurturing fish in a closed-loop system was nothing short of fascinating.
The large food-grade tanks I originally imagined were difficult for me to source secondhand, so I began looking more seriously at the aquariums I already had. Rather than let the lack of a large tank stop the experiment, I reconsidered what could be learned from a small system.
A Game-Changing Revelation
The important lesson in that magazine article was not that a ten-gallon aquarium could grow food fish to maturity. It was that a small tank could demonstrate the basic connections between fish, bacteria, water and plants. That distinction gave me permission to experiment with equipment we already owned while keeping a larger, more suitable fish-growing system as a separate goal.
The idea had come from a magazine article describing how a ten-gallon aquarium could be used to demonstrate aquaponics.
A smaller setup would not support a full-sized fish harvest, but it could help me understand circulation, plant containers, water conditions and the daily responsibilities of caring for fish. As an avid gardener, I was no stranger to friends offering me their old fish tanks, often with the suggestion to repurpose them into terrariums.
Space was limited, so any system would need to fit the room and be accessible for feeding fish, checking the water and working with the plants. Those stored tanks finally gave me a way to begin without purchasing a large fish reservoir.
The 29-Gallon Catalyst
We did not start with a brand-new aquarium. The 29-gallon tank had been given to me, and we checked its condition before putting it back to work. With any secondhand aquarium, inspect the glass and silicone seams and test for leaks before introducing fish. Never use household detergent to clean a fish tank. Saving money by reusing equipment makes sense only when the equipment is safe.
That little tank was an experiment, not our final plan for raising tilapia. I had learned the importance of adequate fish space long before. Once, after a fishing trip, I brought home a catfish because I wanted to keep it. Within a couple of hours, watching it in a ten-gallon tank made it clear that the fish was simply too large for that space. We took it back and released it. I remembered that lesson when we began planning a larger home for our tilapia.
To my surprise, when I finally decided to inspect these tanks, I found several empty ones languishing in my greenhouse and garage. Among them was a twenty-nine gallon tank, alongside several ten-gallon ones. I decided to put the twenty-nine gallon aquarium, which had once housed carnivorous plants. The 29-gallon aquarium was a manageable size for learning, although it would never be appropriate as a permanent grow-out tank for a dozen adult tilapia. That distinction matters when a small experimental setup involves living fish.
Crafting the Foundation
A 29-gallon aquarium holds more than 240 pounds of water before you add the glass, growing media or equipment. That made the stand more than a decorating decision. Jerry and I cleared a sturdy metal shelf and planned the placement so we could reach the fish tank for feeding, cleaning and testing without moving the entire system. I would never put an aquarium on a shelf without checking the manufacturer's weight rating and making sure the surface supports the tank correctly.
We also had to consider the grow light and electrical cords. Water and electricity require extra care: use GFCI-protected outlets, arrange drip loops below plug connections and keep power strips away from splashes. Grow lights should be positioned according to the fixture's instructions and the needs of the crops. A setup that is difficult to reach will be difficult to maintain, so leave room to inspect the pump, lift a plant container and respond quickly when something needs attention.
With the twenty-nine gallon tank in mind, the next step was setting up a sturdy foundation. I enlisted the help of Jerry, and together, we cleared off a reliable metal bookshelf that would serve as a stable stand.
The bottom shelf became the new home for the aquarium, while the top shelf awaited the arrival of our verdant companions, basking under the gentle glow of a strategically positioned grow light.
As I meticulously cleaned the tank and prepared everything for its new occupants, my thoughts drifted to a beloved variety of fish - catfish. These delectable swimmers held a special place in our hearts, and I yearned to have them as part of our aquaponics journey. However, a harsh reality struck - there were no local sources for catfish at the moment.
Why We Started With Tilapia
Choosing tilapia instead of catfish did not mean I was new to keeping fish. I had cared for aquariums since childhood, but raising tilapia in a system intended to feed plants presented new questions about temperature, waste production, filtration and the space the fish would eventually need. We could learn from the smaller setup while planning for a much larger home as the fish grew.
Rather than wait until spring to find catfish, I began looking at other fish that might be available locally. I knew that come spring, the itinerant fish vendors would set up shop at Tractor Supply, offering me the opportunity to acquire catfish.
In the interim, a delightful turn of events unfolded as a kind couple sold me a dozen tilapia. This unexpected surprise fulfilled my Christmas wish, albeit a humorous one: "two catfish and one aquaponics setup."
Connecting with Fellow Aquaponics Enthusiasts
Meeting growers who were already keeping tilapia in an aquaponics system helped me think beyond the excitement of assembling equipment. A working system involves daily feeding, checking the fish, inspecting circulation and watching how the plants respond. Seeing their larger arrangement reinforced the need for more room as fish grow and gave us ideas for the larger system we hoped to build.
I enjoyed talking with the couple who sold us the tilapia because they were already working with a much larger aquaponics setup. It reignited my passion for gardening and, more poignantly, my longing for my greenhouse. Our conversations flowed, and their aquaponic setup painted a vivid picture of what was possible.
Seeing the couple's larger aquaponics setup gave me a better sense of the space, equipment and day-to-day work involved. Their experience was valuable, but I knew our smaller aquarium would have different limits, especially as the fish grew.
Their setup also reinforced why I wanted to get my greenhouse back into shape. A protected growing space would make it easier to plan a larger system and manage temperature changes in Indiana. I wanted a system that could support the fish properly and give the plants enough light and room to grow, not simply a bigger version of the aquarium experiment.
Aquaponics Equipment: What We Needed and Why
The equipment has to do more than move water from one place to another. A reliable pump, secure tubing, a drain that cannot easily clog and enough oxygen for the fish and bacteria all matter. Check a pump's flow at the height the water actually needs to travel, since its advertised maximum flow may be measured with no lift at all. Test the return path before adding fish, and check it again after moving pots or changing the growing media.
Water is heavy, too. Even before adding gravel or plants, 29 gallons of water weighs more than 240 pounds. A level, sturdy stand is essential, and aquarium electrical equipment should use GFCI protection and drip loops. An air pump and a plan for power interruptions become more important as fish grow. A pump failure is not just an inconvenience to the plants; it can quickly affect oxygen and water quality for the fish.
Maintaining the Ideal Temperature
Water temperature affects a fish's appetite, metabolism and stress level, and warmer water holds less dissolved oxygen. Tilapia prefer warm conditions, but that does not mean every herb or vegetable will want the same temperature. A dependable thermometer and regular checks are essential, especially in a small volume of water where conditions can change quickly.
I would also monitor ammonia, nitrite, nitrate and pH rather than judge the system by clear-looking water. Beneficial bacteria need time to establish themselves, and a new tank can accumulate harmful fish waste before the biological filter is ready. Fish stocking must be based on the mature system's filtration, aeration and volume, not on how many fingerlings happen to fit in the aquarium.
Promptly, I installed an aquarium heater to ensure the water temperature remained conducive to their well-being. To further safeguard the fish, I planned to purchase a thermometer to monitor conditions diligently.
Pebbles or Clay Rocks?
Expanded clay pebbles are lightweight, porous and reusable, making them useful in many media-bed systems. Gravel can work too, but it is much heavier, and some stone changes the pH of the water. Growing media should be thoroughly rinsed before use so dust does not clog pumps or cloud the fish tank.
The important question is what happens at root level. Roots need access to water and oxygen, while the containers must allow reliable drainage. I already had pots and some media from hydroponic experiments, but adapting them meant checking the size of the holes, the return flow and whether loose media could escape into the plumbing.
While I did have some from an old hydroponic setup that no longer worked, I needed more. Unfortunately, hydroponic stores were not easily accessible.
Still, I remained hopeful that I'd stumble upon a source for free or affordable pebbles, given my shoestring budget.
The Search for a Pump
A pump must deliver enough water at the actual height of the grow containers, not merely at the flow rating printed on its package. Before adding fish, test the tubing, drains and return line with the plant containers in place. Watch for leaks, overflowing pots and loose connections. In a small system, a pump failure can affect both the plants and the fish quickly, so reliable aeration and a backup plan matter.
The next challenge was finding the pump I thought we already had somewhere in the garage. If luck wasn't on my side, a local pet store had a reasonably priced alternative, only requiring the addition of a hose to complete the setup.
Containers for Plant Growth
A plant container has to support a mature plant, not just a seedling. Basil and parsley can be harvested regularly, but a vigorous tomato can quickly demand a larger root area, sturdy support and more light. Its roots can also grow into water outlets and restrict flow, so I would check the plumbing frequently as the plants developed.
The drainage holes must be large enough to let water move freely without allowing the growing media to wash away. Net pots and suitably perforated containers can help. Any reused container should be clean and made from material appropriate for food-growing use, particularly when it will remain in contact with recirculating water.
These containers needed to facilitate the free flow of water. I contemplated using gallon food-grade buckets, a gift from my friend Shirley a few years ago. They already featured substantial holes at the base, and I believed they possessed adequate space for various edible plants, including tomatoes. However, the lingering concern was whether the holes were too large. Fortunately, I had plastic flower pots from an old hydroponic setup in the greenhouse, serving as a viable backup plan.
Dreaming Big with Aquaponics
The 29-gallon aquarium was our small-scale experiment, not the system we ultimately hoped to build. Jerry and I were a team on projects like this. We had obtained large square plastic IBC totes with plans to set up a bigger aquaponics system and give the tilapia the space they would need as they grew. Our fish in the smaller setup did get quite big, although they never reached harvest size. I already knew from years of keeping aquariums that a fish's needs have to come before the excitement of an experiment.
We never got that larger system running. The greenhouse suffered major hail damage, and Jerry passed away before we could finish what we had planned. We had always worked together, and losing one half of that team changed what I could realistically take on. Building and maintaining a larger fish-growing system, especially without a suitable greenhouse, was not something I could simply pick up and complete alone.
That does not mean I have given up on aquaponics. I would still love to try again someday with larger tanks and a properly planned growing space. The little aquarium project taught me a great deal, and it remains part of a much bigger idea that I still care about. The original goal was to start small, observe the fish and plants, and work toward a larger greenhouse system when we had the equipment and space ready.
The IBC totes we obtained would have been the foundation of that expansion. Before stocking larger tanks, the system would need dependable filtration, biological cycling, aeration, a way to manage water temperature and enough grow-bed capacity to use the nutrients produced. A larger aquaponics setup can grow a useful range of crops, but stocking density and plant demand must be balanced. Fish need room and good water quality even when the plants are growing vigorously.
Seeing what other growers accomplished encouraged me, but their results also reminded me that successful systems are designed around the fish, the plants and the grower's ability to maintain them.
Why I Still Want to Grow Food This Way
Aquaponics appeals to me because it brings fishkeeping and growing food into one working system. It is not effortless, and it is not automatically more sustainable than other growing methods. Pumps, aerators and heaters use electricity, fish require appropriate feed, and water testing is part of the routine. A recirculating system may use less replacement water than some conventional methods, but its actual impact depends on how it is built and maintained.
If I build another system, I want to start with a realistic plan for the mature size of the fish, the amount of filtration they will need and the plants I hope to harvest. I would also plan for power interruptions and for the temperature changes that come with growing in Indiana. I still love the idea of stepping into a greenhouse to tend the fish and pick fresh herbs, and I would like the next attempt to build on everything the first one taught me.
Growing more of our own food has always mattered to me. Aquaponics appealed because it could potentially add fresh herbs and vegetables to what we already produced through other gardening methods. I saw it as an opportunity to bolster our food production capacity, not only to benefit our family but also to contribute to local food pantries and assist those in need.
What I Learned and What Comes Next
For anyone thinking about a similar project, I would begin by deciding whether the goal is to learn how aquaponics works or to raise food fish to maturity. Those are two very different starting points. A small aquarium can demonstrate water movement and plant growth, but the fish species, adult size, filtration and oxygen requirements must determine how much space is needed. The plants do not make an overcrowded tank safe.
Plan the system on paper before adding water. Identify the fish tank, grow containers, pump, biological filter, aeration, overflow route, lighting and power source. Then consider how you will test the water, remove accumulated solids, clean equipment and respond to a power failure. Cycling the biological filter before introducing the planned fish load is an important part of that preparation. Once the system is running, observe the fish every day and keep track of water conditions and plant growth.
I originally imagined harvesting fish from a future larger system. The aquarium project itself became a chance to learn about fish care, plant growth, circulation and the limits of a small setup. At the beginning, I hoped the fish might eventually become part of our food supply. Actual growth time and harvest size depend on species, temperature, feed, water quality and especially the available tank volume. A 29-gallon aquarium should not be presented as suitable for growing a dozen tilapia to harvest weight.
The tilapia grew quite large for our little experiment, though not to harvest size. The plants taught us plenty as well. For the practical results, including herbs, tomatoes and equipment lessons, see my 29-gallon aquaponics tank update.
Are you considering aquaponics for your garden?
Whether you're a seasoned enthusiast or just dipping your toes into the world of sustainable gardening, I hope my experiences have shed light on the possibilities and challenges of this exciting journey. I still hope to try aquaponics again with larger tanks someday. For a look at what we learned from the original setup, read my 29-gallon aquaponics update.
Frequently Asked Questions About Aquaponics
Q: How do you grow tomatoes in aquaponics?
A: Growing tomatoes in aquaponics is feasible. Use larger containers with a well-draining media for the plants. Ensure they receive adequate light, and maintain water temperature and pH levels suitable for tomato growth.
Q: Can you have an aquaponics herb garden?
A: Absolutely! Herbs like basil, cilantro, and mint thrive in aquaponic systems. Plant them in suitable containers and provide proper lighting and nutrient-rich water.
Q: What are the best house plants for an aquaponics fish tank?
A: Houseplants like pothos, peace lilies, and spider plants can thrive in an aquaponics fish tank, helping to filter water and add a touch of greenery to your space.
Q: How do you set up an aquaponics fish tank?
A: Setting up an aquaponics fish tank involves combining a fish tank with a grow bed, ensuring water circulates properly. You'll need a pump, grow medium, fish, and plants. Regularly monitor water quality.
Q: Can you grow carrots in aquaponics?
A: While carrots can be grown in aquaponics, they require deep containers with loose, well-draining media. Ensure consistent water quality and depth for successful carrot cultivation.
Q: How do you grow lettuce in aquaponics?
A: To grow lettuce in aquaponics, use shallow containers with a suitable media like pebbles. Provide proper lighting and maintain water conditions conducive to lettuce growth.
Q: What types of pumps are used in aquaponics systems?
A: Aquaponics systems typically use submersible water pumps or air pumps to circulate water, deliver nutrients, and maintain oxygen levels for fish and plants.
Q: What size tank is ideal for aquaponics?
A: Tank size must be chosen for the fish species, number of fish, filtration, aeration and the system's mature stocking plan, not simply for the available floor space. A small aquarium can be useful for learning about plants and water circulation, but it is not a suitable long-term grow-out tank for large food fish such as tilapia. I intended our 29-gallon aquarium as an experiment and hoped to expand into large IBC totes.
Q: Are there aquaponics greenhouse kits available for purchase?
A: Yes, you can find aquaponics greenhouse kits that include everything you need to set up a controlled environment for your aquaponics system, making it easier to grow plants year-round.
Q: Is aquaponics suitable for Indiana's climate?
A: Aquaponics can thrive in Indiana's climate with the right greenhouse setup. It allows you to control environmental conditions, enabling year-round cultivation despite seasonal changes.
Q: Can aquaponics be used to grow flowers?
A: Yes, aquaponics is versatile enough to grow flowers. With proper care and attention to water quality, you can cultivate a wide range of beautiful flowers in your aquaponics system.
