Want to grow organic plant food, reduce pollution and water usage, and do less gardening work? You can do just that with an indoor goldfish aquaponics system. In other words—goldfish and lettuce go hand-in-hand!
How does a goldfish aquaponics system work?
Aquaponics is a combination of aquaculture (growing fish) and hydroponics (growing plants in water). In an indoor aquaponics system, both fish and plants are housed together to create a self-sufficient ecosystem that requires little maintenance and effort once it’s set up. Goldfish aquaponics are an ideal setup for a beginner to learn the principles of aquaponics.
Fish produce waste (ammonia), which pollutes the water and is toxic to the fish if left to build up. Bacteria convert the waste into nitrate, which is a great fertilizer for plants. The plants feed on the nitrogen and clean the water at the same time, and this clean water is returned back to the fish. The cycle repeats over and over, thus providing the perfect solution for both the plants and fish.
What are the benefits of having an indoor aquaponics system?
Whether you’re keen to create a small lettuce aquaponics system on your kitchen bench or a sprawling aquaponics gardener’s paradise as a feature wall, there are many benefits to having an indoor aquaponics system.
- You’ll grow delicious, organic fruit and vegetables since you can’t use harsh chemicals that will harm fish
- Grow food anywhere all year round without relying on soil—in your kitchen, bedroom, office, garage or even basement!
- Uses 90% less water than soil-based gardening as water is re-circulated
- You can pack plants more densely than in soil
- Plants grow 2–3 times faster than in soil since roots don’t have to fight through soil to get to nutrients and the plant can divert energy to growth
- Plants also grow 10–30% more fruits and vegetables than when planted in soil
- Easier than regular gardening as no soil digging or weeding is required
- Easier than regular fish keeping as plants do the cleaning work
What fish is best for aquaponics?
The fish you select for your indoor aquaponics system should have similar needs as your plants.We recommend goldfish as the ideal choice for aquaponics, particularly if you’re just starting out. Not only are they inexpensive and will look fantastic in your home, but they’re also a hardy species and easy to take care of. Goldfish can survive in a wide range of temperatures and conditions, polluted water and changes to water pH levels. They also do a great job of producing lots of beneficial waste nutrients for your plants and are perfect for starting up your goldfish aquaponics eco cycle.
How to set up a simple DIY goldfish aquaponics system at home
Step 1 – Decide on the type of system
Whilst there are different ways to build an indoor aquaponics system, a common method is to set up a media bed. In this system, plants are grown on a bed, such as pebbles, and this media bed sits above a fish tank. A pump draws water from the tank and flows it through the media bed, enabling the plants to draw nutrients from and filter the water before it flows back to the fish.
Another common and easier method allows the plant’s roots to drop into the water and draw nutrients directly from the water.
Step 2 – Set up your fish tank
The first step is to put your fish tank together, which can be a standard acrylic aquarium or any large food-grade container, and fill it up with water.
Depending on the size of your tank and choice of setup, you may need a pump to assist with water flow to your plants. Allow the water to cycle for 4–6 weeks before adding fish, to give bacteria time to build up and ensure there is enough present to break down the ammonia and nitrites into the nitrates needed to feed your plants.
Choose and set up a container in which your plants will grow (i.e. your media bed), such as a sturdy plastic tray or pallet crate, and fill it with your chosen media.
Step 3 – Add your goldfish and plants
Leafy plants have low nutrient requirements and are generally the best choice for your beginner indoor aquaponics system. Most leafy green vegetables and herbs are easy to grow, such as lettuce, spinach or kale. Watercress, mint, basil and chives are great herbs to try and many common indoor houseplants such as Pothos, English ivy, peace lily and more will also grow. With a more established tank and lots of fish, you can grow fruiting plants and vine vegetables such as beans, tomatoes and strawberries.
Step 4 – Maintain your system
After the initial setup, you’ll need to maintain your system, which is minimal. Feed your fish simple but quality flake food 2–3 times a day, giving them only as much as they can eat in five minutes. You may also consider using a testing kit (to check ammonia, nitrates and nitrites) in the first few weeks to check if your plants are doing their job right or if you need more or less fish to balance the waste.
Commercially available indoor aquaponics systems
Do you like the idea of goldfish aquaponics but don’t feel confident in building your own system? Don’t worry! There are simple, all-in-one kits available that will have you growing plants and edible greens in no time. Below are a few of our favourite indoor aquaponics systems:
This plant holder functions as both a “vase” for your plant and a tank for your fish. The ultra-clear planter includes ceramic growing substrate and planting lid, and suits most indoor houseplants, leafy vegetables and herbs. It’s also easy and simple to clean.
This no-hassle, mini ecosystem comes with everything you need to start growing microgreens in just 10 days. It comes with a small tank, water pump, natural water conditioners, grow stones, months of certified organic microgreen seeds, fish food and even a coupon to choose your fish!
With this kit, you’ll transform your standard 10-gallon aquarium into a flourishing aquaponics ecosystem. The modern, matte black design will look great in any space and can be easy assembled without the use of any tools. It’s fully equipped with a pump and timer, light bar, grow media, and step-by-step guide to setting up and caring for your garden.
Setting up an indoor goldfish aquaponics system, whether in your home or office, is a fun and rewarding way to grow a variety of greens, herbs, vegetables and decorative plants all year round while admiring the natural symbiotic relationship between fish and plants. All you need to do is feed your fish, provide the right light environment, perhaps using LED grow lights if natural light is limited and your vegetables will grow faster and better than any garden plant!
