A good quality water pump and also a suitable one is essential for an aquaponics system. It enables your system to be efficient when transferring water from the tank to the plants and back down again.
Aquaponics enthusiast Aron Stock has a good explanation of how to choose the right water pump. Read on or scroll down to the bottom to watch the full video.
How Many Watts Does It Use?
“There’s kind of two considerations. One is, you want to look at the electronic specs for your water pump. Basically what you’re looking for is the wattage. How many watts does it use?”
“You want to get a water pump that does the job with using the minimum, smallest amount of watts that you can find. The lower the watts, the less money it’s going to cost on your electricity bill because your water pump in most cases, unless you’re on a timer, but in the system I’m doing, the water pump is going to be running 24/7.”
“So it’s really important to get the smallest wattage that you can to use the least amount of electricity, it’s good for the environment and it’s good for your pockets so you’re not paying a bunch of money to the electric company Also, you have to consider how much the pump costs to buy.”
How Much Water Can Be Pumped?
“The other consideration is how much water can you pump through the pump. One kind of rule of thumb you can go with is if you have a 100 liter set up, you want to be able to pump 100 liters per hour. But, when you get into the details of water pumps, you start looking at what is 100 liters per hour?”
“Well, the amount of water that can get pumped through a water pump changes for a lot of factors. The horizontal length of how far does the pump have to go, how much hose do you have…the longer the hose length, the less powerful your pump is going to be.”
“Also, even more so, the vertical height, how far does the water have to get pumped up. That really reduces the pumping capacity of your pump. Hopefully your pump company will have a graph which shows the maximum head, which is how high it could pump, and then it shows you a graph of how many liters per time [per minute or per hour] at different lengths and heights that the pump is able to produce.”
Analyzing The Graph
“You need to make sure that your pump is submersible because it will be pumping from underwater. You also need to make sure that it’s rated for pumping water and not some other fluids.”
“Active Aqua company, submersible pump 250. It can pump 250 gallons per hour. Now I’ve got 100 liters of water in my setup, which is about 30 gallons so obviously this is overkill.”
“However, if we look at the manual, we’ve got a graph here, and here is the 250, that’s my model and this is the grey line here (refer to the image on the right) so you can see the maximum head, maximum height it can go is about 6 feet.”
“Once you reach 6 feet in height [pumping the water up 6 feet], that’s where the pump seizes to work. So if you have to pump the water up 6 feet, you’re basically not going to get any water. If you go down to 5 and a half feet, you’re going to get a trickle of water. If you go down to 4 feet, you’re going to get about 30-40 gallons per hour. Now that’s OK for me because my setup needs the pump up about 3 feet. So with this pump, pumping up 3 feet, I’m going to get somewhere around 60GPH, and I only need pump 30GPH because I have a 30 gallon setup (100 liters).”
“So it’s better to have too much. You need a pump that can overdo it a little bit. Basically, if your pump is a little bit too strong, you can always use some kind of a valve to slow down the water flow or you can divert the extra water and help aerate your fish tank or something.”
“Make sure your pump is more than capable of doing the job. You don’t want to go overboard and get a humungous pump cos then you’re running too many watts and using up tonnes of electricity, but you want to get a pump that’s good enough, that’s definitely strong enough to handle what you need to do with leftover power to spare.”
Water Pump Overview
“Basically, the water gets suck in through these little grates, and there’s kind of a propeller type fan which is essentially blows the water up and out the top fitting. So this top fitting has screw threads, and it comes with some different fittings. They screw into the top, and there’s a couple different fittings for a skinnier hose or a fatter hose.”
“…One really cool aspect of this pump which I can hopefully utilize is that it comes with an attachment here that has a venturi…It’s a way to help aerate your water without using any aerator pumps or any electricity. It’s just a natural plumbing method of increasing the air intake into your water. Basically as the water goes through the pipe, it pulls air in through this air hose, so it mixes a little bit of air in with the water.”
“Most water pumps have some sort of way to regulate the water output that they can do and with my pump, this is one of them. Water gets sucked in through here because the fan (the propeller blades) is pulling the water in and pushing up.”
“I’ve got this guy here (the regulator fitting) and by twisting here, you can close the gate. So obviously if the doors open, more water can get pulled through, but if you need to lessen the amount of water, you just close it and the water only gets pulled through here (the grate openings on the pump).”
“When you take it apart, this is the actual pump. Inside here, that’s where the propeller blades spin to pull the water through. It’s got some suction cups (beneath the pump) so you can stick it to the bottom or the sides of your tank, and then you got your filter material.”
“It’s kind of some spaghetti foam so that none of your big fish solids are going to get stuck inside the propeller fan blades. Once a week or so, you’re going to have to clean this out. It’s going to get gunked up with fish poo.”
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.