Fish to plant ratio
Here you, came the time when you were in front of your first ever aquaponics system and you were wondering how many fish can you "stock" in there... For many it is a challenge, for a few it is a gamble and the rest, they follow a certain ratio.
Define your growing space
I have been asked this more than one time and it is not that I pull numbers out of a hat instead, I am following established rules.
The following is working for backyard growers using media based growing systems, either in an IBC or barrel or whatever suits your need. Balance is what we are aiming in order to have a healthy and thriving ecosystem - overload doesn't work.
Tank volume as your base is not a good idea. Aquaponics is about bio filtration and so it depends on the size of your bio filter aka the grow bed. Bacteria will process the waste from the fish and turn it into plant available nutrients. Remember, in a previous post, I talked about the Nitrogen Cycle where I explain the role and nature of the bacteria in our grow beds.
In a media bed, only the submerged portion of it allows for the bacteria colony to thrive so it is this part that is of interest in order to size your stocking density.
For the advanced aquaponists here, you may have heard about Biological Surface Area aka BSA. This is in relation to the media in the grow bed. The whole media surface, in our case clay pebbles, have a very porous surface and holding water in tiny pockets; this is paradise for our nitrosomonas and other nitrobacter.
Onto the calculations
I will use metrics as I am French and don't find any logic in the imperial system but for you, folks out there, I will give you a break and make a rough translation. Note here that my numbers once translated into this weird measuring unit may differ from what you'd get if you spoke the Imperial lingo... Anyways, without any overdue, take a pen, a paper and a measuring tape. Or if you use an IBC type system, you can use my measurements as they come from that model of aquaponics setup.
For the Imperialists out there, you have 47'' in length, 40'' width and 10.24'' high. This gives you a total of 19,251.2''3 (cubic inches). You most likely know that you have 231''3 in 1 gallon, therefore, 19,251.2/231=83.33 gallon.
This is your total submerged media volume.
The rule of thumb
Now that we know our total submerged media, we are able to find out how many fish we can put in our fish tank. Assuming we are using appropriate aquaponics solid media, of course.
So it goes as such:
In Imperial, 83.33 / 6.6 = 12.6 fish ( round it down to be conservative)... So more food for the Metric people! :)
As far as stocking fish in a tank like an IBC, yet another rule of thumb to follow is for every fish you want to grow out to harvest size, you need 25lt of water. An IBC holds approximately 1000lt and so you could stock up to 40 fish in that volume of water.
It is recommended to add fish progressively to your system after it has cycled. The bacteria colony must be looked after and developed enough to sustain the fish waste load you will give it to chew on.
So very important to log your water parameters often at the early stage and on a regular basis once fish are in the system. An ammonia or nitrites spike is lethal for the fish and can happen really fast.
I hope this article will help you start on a good foot and enjoy the reward of a thriving and healthy aquaponics system.
Prevention - Monitoring - Treatment
Since our United Arab Emirates summer is now behind us, life doesn't get any easier for gardeners and farmers alike. This is what gave me the idea to write this article or more likely, this series of articles. There are many pests susceptible to infest our greens and flowers.
Let me know if you enjoy the read and share with us if you use different methodology.
A water savvy system that could help remote communities.
Aquaponics as such, has a great potential to be used in developing nations - not only as a commercial venture but as a mean to produce food for the population of these countries.
Aquaculture advocates also say it is sustainable and Eco-friendly. Water is a precious commodity in developing nations, and because the majority of the water used is recycled through the aquaponics system, significantly less water is consumed than in traditional agriculture. The possibilities are limitless
It could improve people in developing countries’ lives by increasing food security, employment opportunities and economic growth.
As nutrition is a key issue for developing nations, relying mainly on staple crops such as wheat and rice, the farmed fish could also provide a valuable source of protein. By building aquaponics systems in developing nations, there would be more food for the population, and it would be more nourishing as well as economically viable.
What is aquaponics?
Having an aquaponics system is fun and very rewarding. Not only for the fresh and naturally grown veggies but also for the knowledge you will acquire along the way. In this article I will introduce you to a very important parameter: the pH. You may have heard about this term, mostly concerning your drinking water. Well, our favourite pets (our fish) as well as our plants like their water to a certain pH and this is for that reason, you will have to test it. So without any overdue, let's talk about potential of hydrogen aka pH.
There is indeed an aquaponics movement picking up in Dubai. I see more and more new comers, residents purchasing from me small systems to put in their backyard or by the window sill. This is very encouraging. And many more come and visit us to see with their own eyes what is this about. I tell you, when they see the papapya tree I have growing in the grow bed and they can compare with the one planted in soil, exactly at same time, they realise the potential.
But these people are expats, no nationals have been visiting so far.
So I decided for this short article to share with you how is the aquaponics doing at the National level.
When you decide to build your aquaponics system, it is important that you take the time to size everything accordingly. There are some ratios to respect. The size of the grow bed according to the size and stocking density of your fish tank and also the filters (if you decide to use any) as well as the heart of your installation: the pump.
There are two ways to bring water to the grow bed: water pump or air-lift with an air pump. In this article I will introduce the two possibilities. Although, note that my preference goes to the water pump :)
When you read about ''cycling your AP system'' doesn't mean taking it on your back and going for spin with your fancy bicycle... LOL I just made that up and the picture I had in mind was very funny. If only I could draw :)
On a more serious note, after reading the previous post, you have a better understanding now of the nitrogen cycle and this is what it is about.
When you finish to build your system and it has been tested for leaks, the siphon is working, you have filled the grow bed with media and should now plug in for, ever, your pump.
Let's see a more in depth approach to cycling an aquaponics system.
When we talk about aquaponics, we can't do so without talking about what makes it all possible. I am talking about the nitrifying bacteria, the Nitrobacter and other Nitrosomonas. Without them, the ammonia excreted by the fish would stay in the water and after passing in the grow bed, where the plants would not like the taste of it, it would go back in the fish tank.
The ammonia is very toxic for the fish and the bacteria we are talking about, are responsible for converting it into nitrites and eventually, into nitrates. But let's take a break here and dive into science a little bit.
I am a French expat, married, dad of one, nature lover and firm believer of sustainable living. My background is leisure and tourism industry. I fell into aquaponics and now I am sharing with you my adventure.