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Growing Onions in Aquaponics Gardens

Growing Onions In Aquaponics Gardens

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Often, merely having a perfectly sliced piece of onion can be the missing link between an ordinary meal and a culinary experience to remember. Even though at times the love for them can make us cry, the ability to cultivate onions in your own backyard may be well worth the pain. Growing onions in aquaponics gardens provide you a sustainable way to yield this crop yourself so that you can enjoy its’ zesty crunch flavor all year round. 

In this article, you will learn more about the benefits of growing onions and the specific requirements you need to grow them through aquaponics.

Why Grow Onions in an Aquaponics System

A 2015 study in Kenya showed that although traditional farming practices were the norm for hundreds of years, it has left the environment destroyed, and 60% of the land deforested due to the expansion of agricultural land.

Therefore if you are considering growing all your plants through aquaponics, you are doing the planet a huge favor. You are not only saving on space, but you are also saving on water and providing sustainable nutrients to your plants from the accumulated fish waste in your system.

Why grow onions in an aquaponic system? Well, aside from the fact that onions are one of the easiest plants to grow when you’re starting out using aquaponics, it also contains a lot of antioxidants that are good for preventing inflammation, and it is a cooking essential especially if you love sauteed meat or even vegetables.

Health Benefits of Onions

Onions belong to the same genus as garlic, shallots, leeks, and chives. Aside from making any sauteed dish or even guacamole taste better, onions are packed with many vitamins and were famously used as a cure for headaches and mouth sores. Onions are nutrient-dense, which means that they are low in calories but have lots of nutrients. This vegetable is rich in vitamin C, folic acid, protein, and no fat. 

A study in China in 2019 showed that eating vegetables from the Allium family can significantly reduce the chance of colorectal cancer by 79%. Amazing, right? Onions are rich in vitamin C, which can help the body’s immune system and help the body’s iron absorption. 

How to Grow Onions in an Aquaponics Setup

How to Grow Onions in an Aquaponics Setup

Onions are relatively easy to grow in an aquaponics set-up. Here are some key cultivation tips when growing onions in aquaponics:

Choosing Types of Onions to Grow

Here are some onions you may want to grow:

  • Bermuda Onions- These onions grow even in less sunlight, making it perfect for indoor growing. You can use this slightly sweet onion for dips and stuffing. This onion takes a full 80 days to mature.
  • Vidalia onions– These onions are sweet, similar to the taste of apples, but to carry this name, can only be grown within 75 miles of Vidalia, Georgia. If you want to plant sweet onions, you can opt for Walla Walla onions instead.
  • Walla Walla Onions– A sweet onion which can replace Vidalia onions, especially if you don’t live in that area. This onion also grows fast at only 65 days. 
  • Spanish onions– These onions need more moisture, so you would need to closely monitor the grow medium (if you use any). You cannot allow the plant to dry as it has a higher water content than other onion varieties making it a bit trickier to grow. The reward is when you harvest them and make them into juicy onion rings. 

pH Levels

Maintain the pH levels at 5.5 to 6.5 when growing onions as this plant grows well in a slightly acidic environment. As always try to use a quality pH meter.

Using Grow Medium

Using LECA (lightweight expanded clay aggregate) can help when growing your onions. It is a growing medium that makes it easier for you to keep your plants hydrated and oxygenated, and it’s light enough to make harvesting easier. LECA is an environmentally-friendly growing medium because it is reusable. LECA is perfect to use during very warm periods (which can cause your onions to dry). To buy expanded clay aggregate click here.


Onions are tough plants as they can withstand the heat and cold, but the temperature has to be between 55°F to 75°F to encourage the bulbs to start sprouting. 


To get big and fully grown onions, make sure they get 6 hours of full sunlight but check for overexposure as it can dry the plants. You can grow onions in partial shade with only 3 hours of sunlight but expect smaller bulbs.   


The science behind aquaponics made it possible to grow vegetables faster, so following the tips given to you above, you’ll definitely grow onions in no time. You can now cook all the healthy and delicious dishes with home-grown aquaponic onions that you worked hard for. If you are looking for onion substitutes for your recipes click here.

The Campbells love finding sustainable and fun ways to increase their independence from traditional brick and motor supermarkets. Aquaponics provides a full lifecycle food source for families and a great hobby. #aquaponicslifestyle

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