Backyard Aquaponics

It really delights us at Ichthys Aquaponics to see how our information and fish are put to great use… Jono from Ladysmith purchased fish 3 months ago and has started a superb system comprising of NFT and AGT which is going really well. Congrats!

Big City Farms construction underway

Ichthys Aquaponics is the lead consultant for a very exciting new startup call Big City Farms. The startup is based in Midrand, and is constructing 2 x 30m aquaponic tunnels to produce high quality organic produce for the ever expanding top end restaurants in Johannesburg and surrounds. The company, BEE certified is aiming to be the largest aquaponics producer of fresh produce in South Africa.

The two tunnels will have a combination of both DWC and ABT beds to grow a wise range of produce. Come back soon to follow the progress of construction and the company.


How many tilapia can I stock my tank with?

A question that I get asked more often than any other, is “How many tilapia can I stock my tanks with”. Immediate answer is how long is a piece of string? There are many factors that determine how many fish you can stock your system with and how sophisticated your setup is.   Two main factors to consider is temperature and oxygen. At higher temperatures the amount of food consumed increases, and oxygen retention of water decreases. Remember even if you have the most advanced oxygen replacement system, the increase of waist from the fish will require adequate filtration and if not careful will result in grow beds and filters getting clogged up quicker than normal. As soon as you start pushing stocking densities of tilapia then many factors

if not careful will result in grow beds and filters getting clogged up quicker than normal

With aquaponics I always rather play on the safe side with the fish, and have found that a stocking density of 25kg (at harvest) per 1000 litres of water at 25-29 degrees celcius to be ideal. At this rate, standard oxygen supplies (air stones / tube) will be more than adequate… Remember that for every litre of water it is recommended to have approximately 3 litres of grow bed (at 20cm to 30cm deep). I have heard of some farmers going as high as 100kg per cubic litre of water – imagine that! The fish would require 24×7 life support and should anything fail in the setup you would have a matter of minutes to resolve the issue… not to mention an enormous amount of fish waste to deal with!

So, once you have worked out the stocking density you want to aim for and have an adequate system designed the formula for number of fish is as follows:-

(Amount of litres in tank) / 1000 * (Stocking Rate (KGs) / Ideal Harvest Weight)

You can also use the calculator below to help 🙂

How good is Talapia for you… really?

There have been numerous articles on how good farmed fish, and in particular tilapia is for us. There was even an article published last year stating that bacon is better for you than tilapia! Truth is that in some countries fish farming has become a corporate affair. What does that mean? Well, essentially a profit factory. In order to maximise profits, fish are being fed crap… yes literally crap as well as GMO pellets… fish are being given hormones to speed up their growth rates… and worst of all fish has been genetically modified to grow quicker!

The more natural the fish diet, the higher the quantity of omega-3 present

The average 4 ounce serving of tilapia has 1 gram of saturated fat, 29 grams of protein, and 200 mg of omega-3. That’s about the same omega-3 content as scallops, wild lobster, wild cod, wild haddock, wild mahi mahi, yellowfin tuna, orange roughy, and shrimp. The omega-3 content is significantly increased if the diet consist of largely natural food source (lettuce, duck weed, lucern etc…)

What you put into the fish is what you get out

Sustainable and well raised fish are the only hope for feeding a hungry planet. Perhaps explaining why Tilapia is the number 4 consumed fish in the world. My favorite way to have Tilapia is as a ceviche – and here is the recipe.  When it comes to food, having this as a basic staple will provide a nutritious source of food for many years.