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 :)
Choosing a water pump is not easy. Finding the right pump is even harder, specially when you live in Dubai. As it was when I was gathering all materials to build my first aquaponics (AP) system, looking and finding the right pump was a challenge of its own. In the end, Dubai has it all, or almost, it suffice to look in the right place. Oh and keep in mind, once you have found where to buy, you'd better buy two, just for the peace of mind in case the one you install in the fish tank dies or fails for some reasons.
So, back to the topic at hand - what size is a good size?
Yes, size does matter in this case. But what are we measuring you would ask?
If we take the example of the single IBC tote AP system, it will operate with the pump in the fish tank and will fill up the grow bed, same as most domestic AP installation. This is one reason why it works so well with these containers because once cut, keeping the top third as your grow bed and the bottom part for the fish, you have 300lt on top and almost 700lt at the bottom.
One very important factor when looking for the right pump, it's the fact that you must "turn over" your fish tank water, at least, once per hour. Here, I just gave it to you; sizing your water pump depends on the volume of your fish tank.
Later on I will talk about two different method pumping the water can be done:timer based or siphon based system.
For now and I will not go into greater details, you need to have a pump that is at least twice your total water volume. As an example, if your fish tank contains 600lt you should get a pump that is rated at 1200lt/hour. The aim here is to counter-act some aspects of your circulatory system in your AP installation, that create drag and other friction, reducing the water flow.
Let's look at the chart bellow;it explains that although you are buying your pump according to the label on the box, in terms of ltr/hr rating, there is something to take into account:the head height or how high does your pump has to send the water (to the grow bed or filter). We could add to this, how many bends and what is the pipe diameter...
We'll leave at that until we are a bit more expert :)
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.