Air Lift Pump in Aquaponics and Aquaculture

air lift pump

An air lift pump is a great idea for backyard aquaculture and aquaponics, they even work well for decorative ponds with low fish stock levels.  Back in mid 2010 a client wanted to build a small backyard aquaculture system he could connect to a hydroponic subsystem (aquaponics) later.  We thought about having a go at using an air pump to move the water about instead of a water pump as a trial with a 125watt air blower.  It was a great little backyard build and it makes for an interesting read for those thinking about using an air lift pump to move water through their aquaponics or aquaculture.

Basic Air Lift Pump

Let’s take a quick look at the system overall.

  • 3 x 720 litre mega bins (hold around 600 liters wth freeboard)
  • 1 x 200 litre drum biofilter/sump (this can be any type of drum but an open top with a lid is handy)
  • 1 x 100 litre hatching hopper/swirl filter (this is the swirl filter it can be any design of swirl or solids filter you like)
  • 1 x 20 liter bucket (this is the packed media solids filter in the center of the swirl filter)
  • 50 litres of Kaldnes or K1 bio media in the 200 liter drum
  • 15 or 20 liters of Kaldnes packed in the 20 litre bucket in the swirl
  • 125 watt side channel blower (the blower is a good choice but lack pressure a smaller diaphragm pump would be more effecient)
  • 3 x 170mm x 40mm air stone diffusers (for the fish tanks)
  • Pipes and fittings.  The pipes in this set up could have been the next size down to prevent any build up of solids in the 90mm supply line manifold but that would make it all pressure fittings.  In this build all were drain waste (DWV) fittings.

air lift pump

The general run of the water through is system is as follows:

  1. Water gravity flows up the 45deg x 50mm pipe into the internal plumbing (see below)
  2. Then out through the 50mm pipe through the wall of the Mega Bin
  3. Each of the three tank outlets then connect to a common 50mm waste manifold
  4. The waste manifold that runs along the back of the tanks connects through the wall of the swirl filter.
  5. Some of the heavy solids (fish poop) fall out of the water to the bottom of the swirl to be drained off the bottom as needed.
  6. The water then must flow up and through the packed media in the 20 litre bucket in the middle of the swirl filter for more solids polishing (see below).
  7. It then exits the swirl filter and is deposited through the wall (uniseal) of the 200 liter drum bio filter with 50 litres of K1.
  8. The bio filter uses a small amount of air through an air stone in the bottom to keep the bio oxygen rich and the media moving.  Hence moving bed biofilter.
  9. The water exits the biofilter clean and into the begining of the common supply manifold.  This starts as 50mm up to the 50mm three way valve then the size after is 90mm.  However this part could remain 50mm all the way.
  10. The supply manifold runs to the end of the three tanks.  At the end is an verticle pipe for cleaning access.
  11. Each tank has a 90mm tee and 90-50mm reducer with the air supply to the base (see below) to lift the water from level into the fish tank (around 100mm head).  The head could be reduced if the supply pipe work came in through the tank wall.
  12. And around it goes again.  We managed to get around 550liters per hour flow rate but it was not greatly efficient with the blower.

air lift pump

The air lift pump assembly was very basic as you see above.  There was no air stone used because we were aiming for a “slug flow” instead of “bubble flow” and the blower would have struggled with additional air stones putting more backpressure on it.

air lift pump

We air lift pump the water with air from the 90mm supply manifold.  In the above photo you will notice the small 13mm irrigation (greenback) valve for controling the air supply and flow rate into the fish tank.  Very simple and usually a set and forget once you have all the tanks ballanced.   Remember you turn one valve and it usually effects all other flows.

There is one basic air lift pump you can make yourself for your system should you want to run it on air.  If not, like this one, you can change it out and add a water pump instead of the airlift pump.  Simple and effective.

Enjoy
Paul.

An air lift pump is a great idea for backyard aquaculture and aquaponics, they even work well for decorative ponds with low fish stock levels.  Back in mid 2010 a client wanted to build a small backyard aquaculture system he could connect to a hydroponic subsystem (aquaponics) later.  We thought about having a go at using an air pump to move the water about instead of a water pump as a trial with a 125watt air blower.  It was a great little backyard build and it makes for an interesting read for those thinking about using an air lift pump to move water through their aquaponics or aquaculture.

Basic Air Lift Pump

Let’s take a quick look at the system overall.

  • 3 x 720 litre mega bins (hold around 600 liters wth freeboard)
  • 1 x 200 litre drum biofilter/sump (this can be any type of drum but an open top with a lid is handy)
  • 1 x 100 litre hatching hopper/swirl filter (this is the swirl filter it can be any design of swirl or solids filter you like)
  • 1 x 20 liter bucket (this is the packed media solids filter in the center of the swirl filter)
  • 50 litres of Kaldnes or K1 bio media in the 200 liter drum
  • 15 or 20 liters of Kaldnes packed in the 20 litre bucket in the swirl
  • 125 watt side channel blower (the blower is a good choice but lack pressure a smaller diaphragm pump would be more effecient)
  • 3 x 170mm x 40mm air stone diffusers (for the fish tanks)
  • Pipes and fittings.  The pipes in this set up could have been the next size down to prevent any build up of solids in the 90mm supply line manifold but that would make it all pressure fittings.  In this build all were drain waste (DWV) fittings.

air lift pump

The general run of the water through is system is as follows:

  1. Water gravity flows up the 45deg x 50mm pipe into the internal plumbing (see below)
  2. Then out through the 50mm pipe through the wall of the Mega Bin
  3. Each of the three tank outlets then connect to a common 50mm waste manifold
  4. The waste manifold that runs along the back of the tanks connects through the wall of the swirl filter.
  5. Some of the heavy solids (fish poop) fall out of the water to the bottom of the swirl to be drained off the bottom as needed.
  6. The water then must flow up and through the packed media in the 20 litre bucket in the middle of the swirl filter for more solids polishing (see below).
  7. It then exits the swirl filter and is deposited through the wall (uniseal) of the 200 liter drum bio filter with 50 litres of K1.
  8. The bio filter uses a small amount of air through an air stone in the bottom to keep the bio oxygen rich and the media moving.  Hence moving bed biofilter.
  9. The water exits the biofilter clean and into the begining of the common supply manifold.  This starts as 50mm up to the 50mm three way valve then the size after is 90mm.  However this part could remain 50mm all the way.
  10. The supply manifold runs to the end of the three tanks.  At the end is an verticle pipe for cleaning access.
  11. Each tank has a 90mm tee and 90-50mm reducer with the air supply to the base (see below) to lift the water from level into the fish tank (around 100mm head).  The head could be reduced if the supply pipe work came in through the tank wall.
  12. And around it goes again.  We managed to get around 550liters per hour flow rate but it was not greatly efficient with the blower.

air lift pump

The air lift pump assembly was very basic as you see above.  There was no air stone used because we were aiming for a “slug flow” instead of “bubble flow” and the blower would have struggled with additional air stones putting more backpressure on it.

air lift pump

We air lift pump the water with air from the 90mm supply manifold.  In the above photo you will notice the small 13mm irrigation (greenback) valve for controling the air supply and flow rate into the fish tank.  Very simple and usually a set and forget once you have all the tanks ballanced.   Remember you turn one valve and it usually effects all other flows.

There is one basic air lift pump you can make yourself for your system should you want to run it on air.  If not, like this one, you can change it out and add a water pump instead of the airlift pump.  Simple and effective.

Enjoy
Paul.

About the author

Paul Van der Werf

Paul is the Operations Manager for a 4400m2 integrated aquaculture pilot project in the United Arab Emirates desert he designed and built. This is a commercial aquaponics pilot to evaluate integrated farming in arid climates.

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9 Comments on “Air Lift Pump in Aquaponics and Aquaculture

  1. Jon

    Hi
    How many fish could each tank Sustain and up to what size?
    I’m thinking of using this setup for common/mirror carp here in the Uk. Fish I have are approx 1.5-2 ”
    Regards Jon

    1. Hi Jon,

      With some filtration as this set up had, you would be looking at up to 12 to 15kg of fish (24 to 30 x 500gram each) each tank.

      Regards
      Paul

  2. Jon

    Wow
    So How many 1-2″ carp would you recommend to start with? I was thinking 1000 split between the tanks

    1. Hi Jon,

      If you plan to grow the carp, stick to the numbers I posted previously.

      Regards
      Paul

  3. Jon

    I was thinking indoors for 6-8 months until reach 4-8″ and then they will be transferred to outdoor ponds.
    Do you have designs for bio filter in a 200l drum?

    1. Hi Jon,

      1000 fish (regardless of species) split over three 600 litre tanks, even with bio and solids filtration, will struggle to survive up to 4 inches long. 555 fish per 1000 litres, grown to 4 inches will give you a stocking density far to high for the system to cope with. Work out the weight of the each fish at 8 inches and design the system from there.

      Regards
      Paul

  4. Jon

    Could I have a sketch drawing of this set up please?

  5. Jon

    Could I please have a design drawing for this whole system?

    1. Hi Jon,

      There was no real design outside of some math scribblings and some crayon drawings which you can see here. Because the set up was small most of it was done in my head.

      I am sure the photos reasonably describe what is needed to build the system.

      Regards
      Paul

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