In this section, I list my best and most insightful tips I’ve learned during my journey in aquaponics.
Here are my top 10 aquaponics how to tips.
1) Choose A Media Bed
I would highly recommend a media grow bed instead of a NFT (nutrient film technique) and DWC (deep water culture), especially if you’re new to aquaponic gardening.
This is because a media bed performs three filtering functions:
- Mechanical solids removal filter
- Breakdown of solids and cycle of water known as mineralization
This basically means that it simply does everything all-in-one acting as a very suitable place for plant growth. Not only is using a media bed cheaper, but it’s also easier to understand.
2) Determining The Size Of Your Grow Bed
The size of your grow bed dictates the amount of plants you can grow and also the conditions of your plants.
The industry standard of a grow bed is set to at least 30cm deep to allow the wildest variety of plants to grow healthy and also to provide efficient and complete filtration.
3) Determining The Size Of Your Fish Tank
At least 1,000 litres or more creates a suitable aquaponics system, so assuming you have the flexibility in terms of space, this is recommended. The more you increase the fish tank volume, the better it is for beginners because it allows more room for mistakes as things tend to happen at a slower pace.
Generally, you would need at least 200 litres volume of water to raise a fish to 30cm in length which is ideal for a “plate size” meal.
4) Determining The Ratio Of Grow Bed To Fish Tank
As a basic rule of thumb, you should start with a 1:1 ratio of grow bed volume to fish tank volume. Once your system starts to mature within 4-6 months, you can increase it to 2:1 if you really want to.
Please ensure that the foundation and supports of your system is sturdy enough to carry the weight of the media, water and plants.
5) How Many Fish Can You Grow?
If you want to find out how many aquaponic fish you can grow, first find out the fish weight required by using the ratio rule of 500g of fish for every 0.1 m² of grow bed surface area. Bear in mind that this is based on the assumption that your grow bed is at least 30cm deep.
Next, figure out the fish tank volume from the rule above which when increased will equate to 1kg of mature fish per 40-80 litres of fish tank volume. Knowing this information will allow you to determine how many fish you can grow in a safe and healthy environment.
6) Getting The Water Temperature Right
Different fishes will suit different temperatures in water, so if you want to be on the safe side, then get fish that are adaptable to various water temperatures, or fish that thrive at the water temperature your system naturally responds to.
Bear in mind that it’s easier to heat up water compared to cooling water. You can attract heat in the water by buying an aquarium water heater or darkening your fish tank. You can do this by covering it with black sheets or even better by buying a black tank.
7) Getting The Water pH Levels Right
Water pH levels rise during cycling and drop after cycling so it needs to be adjusted. Maintaining the right water pH levels is essential for your fish, plants and bacteria to thrive. You should target a pH between 6.8-7.0 in your aquaponics system.
If the pH level drops below 6.6, the best way to raise it is to use hydrated lime (calcium hydroxide), potassium carbonate or biocarbonate. If pH goes above 7.6, to bring it down use hydroponic acids such as nitric or phosphoric. Test pH levels every week (around 3-4 times).
8) Getting The Right Fish
The fish you choose depend on three factors:
- Whether you want to eat them or simply showcase them
- The climate and/or water temperature of your location and/or aquaponics system
- Whether the fish are carnivores, omnivores or herbivores
Once you know the answer to these, which can only be answered by yourself, then you will know what fish to get. You should keep fingerlings separate from mature fish as they may be eaten by them. To find out more about aquaponic fish, check out the Top 7 Aquaponics Fish Species guide.
9) Feeding Your Fish
An adult fish will eat roughly around one per cent of its own body weight every day while baby fish (fry) will eat as much as seven per cent. So as a rule, you should feed your fish as much as they’ll eat in five minutes for one to three times per day.
It’s important not to feed your fish too much food. If you notice that your fish are not eating anything, this should ring alarms and it probably means that they’re under stress as a result of not being in their optimal temperature range, don’t have enough oxygen or the water pH levels aren’t right.
10) Growing The Right Plants
Nearly all types of plants can be grown well in aquaponics, even the likes of tropical plants. However, you may want to avoid plants that prefer an acidic or basic soil environment.
Just like plants raised in a soil garden, plants for aquaponics can be started just the same by seed, cuttings or transplant. Keep an eye out for insects that will eat away at your plants making them unhealthy after the first few months.
Also, just like for fish, water pH levels are important for your plants to thrive. You must maintain a pH of 6.8-7.0 for optimal nutrient uptake by your plants. For more tips on growing plants, check out the Top 7 Tips For Growing Aquaponic Plants.
To get the most out of your aquaponics system, I highly recommend the following articles, where you can decide from the highest rated and bestselling products for aquaponics.