When you are doing aquaponics you stumble over quite some technical difficulties.
One of those is selecting the right pump for your aquaponics system.
In this article, I’m going to teach you how you can select the right pump for your aquaponics system.
Let’s get started!
What is your desired flow rate?
You will decide the flow rate of your aquaponics system by the fact that the water in your fish tank needs to be recirculated every hour.
If you have a DIY aquaponics IBC setup, this would mean you would need to have a pump with a rating of at least 250 gallons per hour.
But this rating alone is not enough, there is something called the head height of a pump which you need to consider as well.
How high do you need to pump?
The next question is how high you need to pump your water to whatever system you are using. If you are pumping from a sump to the fish tank, you can have a few feet of head height.
When you are designing your system, you need to design it in a way that there is not much head height. Less head height will require less energy consumption, which means money saved.
In the following image, you can see what head height really is. Now, decide what your head height will be of your system and keep that in mind for the following step.
What is the head height of a pump?
Let’s say you bought the 250 gallons per hour pump for your IBC system. The pump tells you it’s 250 gallons per hour so it should pump 250 gallons per hour in my growbeds, right?
You see, the flow rate of a pump is described with zero feet of head height (elevation). This means the pump will deliver 250 gallons per hour without lifting it up to your growbeds. The flow rate will decrease once you are pumping water up.
Luckily there are charts available for a pump that will indicate flowrate with a certain amount of head height. Below you can see such a curve which is called ‘the pump curve’ which puts the relation between flow rate and head height in a nice graph.
Reading the pump curve
Every decent manufacturer or seller will have a pump curve in their user manual or datasheet. If you can’t find it on their page try to search for: ‘name of pump + user manual’ and with a bit of luck, you should see a nice curve.
Once you have found the pump curve of the pump you want to use, you need to look at the left axis first. Find the head height you calculated for your system and draw a line to the right. Next, look for your required minimum flow rate and draw a line vertical. The point where these lines cross is your pump ‘working’ point.
In this example, it’s right on the 400 GPH pump line.
If your working point is between two pump lines, you need to move up to the right. Never go to the left because you won’t make the recommended minimum one hour recycling time of the water.
You always need to oversize your pump because it’s better to pump the water around more than once an hour instead of less.
In the image above I used an example of an IBC as a fish tank with some grow beds next to it. The volume of the IBC will be around 250 gallons (fully topped). The point where the two lines cross will be your desired pump flow rate. As you can see, If we would have taken the 250 gallons/hour pump we wouldn’ make it to 250 gallons per hour.
Instead, we chose for the 400 gallons per hour pump if we actually want to pump at least 250 gallons per hour.
The best pump for aquaponics
Hydrofarm is a trusted brand and they provide their head height curve data to the user.
They have pumps available at different flow rates:
- 40 GHP or 150 LPH
- 160 GPH or 600 LPH
- 250 GHP or 950 LPH
- 400 GPH or 1500 LPH
- 550 GPH or 2080 LPH
- 800 GHP or 3000 LHP
- 1000 GPH or 3785 LPH
Click here for more information about this pump on Amazon.com
The pumps they supply are also BPA free and comes with a one year warranty which is a nice bonus.
How should I use my pump, inline or submersed?
Most people submerge the pumps in their water tank or IBC. You have to be careful that the electrical plug doesn’t get wet while doing this kind of setup.
How can I connect my pump to PVC piping?
Take note of the fitting of the pump and go to your local hardware shop. They have the fittings you need to screw in the pump.
The pump comes with two fittings but they are used to connect to a flexible hose. If you do not plan on using a flexible hose, you can use these measurements to get some fitting adaptors from the hardware store.
What size pump do I need for my aquaponics system?
The size of your aquaponics pump depends on two items. They are:
- The head height of your pump
- The size of your fish tank