Modular "Lungfish" Ebb and Flow Hydroponics or Aquaponics Systems. Easier?

Introduction: Modular "Lungfish" Ebb and Flow Hydroponics or Aquaponics Systems. Easier?

Lungfish hydroponics aims to produce a modular ponics system where each module can be independent and easily switchable. It uses an external air pump to simplify the whole system. Blocked filters will be a thing of the past because there will be no filters! It is called "lungfish" because the underwater ebb and flow air container can act as a "Lung" to transfer oxygen to the nutrient solution.

Step 1: Using Easily Available Materials.

A key to widespread use of DIY hydroponics is reusing various easily available products in the system.  Another key is to keep the technology as simple and as "low" as possible. A 3rd key is modularity. Parts of the system can be modular so that they can be removed or adapted or replaced by a superior module as the system matures.

Step 2: Geyser Control Module, the Only Technically Difficult Part in the Whole Project!

This is the part I need to simplify.  Or replace! Because it is a modular system, a replacement that works quite differently could also perform this switching operation.  In th current system it is made from an energy drink bottle and a rubber bung with 2 holes drilled in it. The tube goes into the bung to let the air out as it cycles. 

Step 3: Perlite Grow Media

The perlite is put on a sink cup stand inside remay or frost cloth and the water ebbs and flows up and down through the perlite. I measure the ebb and flow distance with a simple manometer.   The system does and ebb and flow cycle in just over 2 minutes on about 2 litres per minute of air from the little aquarium air pump.

Step 4: Air Pump

I used a 2 outlet aquarium bubble pump.  This one is capable of 3 psi (enough to push air about 7 ft deep in water and about 2 litres per minute of air. 

Step 5: Preliminary Conclusion

We only need an ebb  and flow every half hour or so and that means this little air pump is ample for at least 5 or 6 of these "systems".  Prognosis   Hopeful!

Step 6: "Timer and Bleed" Alternative to the Geyser Switch to Control Ebb and Flow on and Off

Another system that would probably work to control ebb and flow is "timer and bleed".  In timer and bleed, your pump is on a timer and it  runs for about 15 minutes, and pumps air into the basins, raising the water level.  The system has a little adjustable  "bleed"  that you can make with an aquarium air valve.  An advantage of timer and bleed is that the roots would be damp but not water logged most of the time.

Step 7: "Flip Flop" Alternative for Switching.

I made a "flip flop" to spread irrigation water from a drip feed across more area in a planter. I think this type of thing could work underwater too.  So when your air gets fairly full in the basin, something flips either in it or outside it and everything empties.  (Outside it is preferred to maintain the modularity of the system).

Hydroponics and Indoor Gardening Contest

Participated in the
Hydroponics and Indoor Gardening Contest

Be the First to Share


    • Baking Contest

      Baking Contest
    • Block Code Contest

      Block Code Contest
    • Make it Glow Contest

      Make it Glow Contest


    wiley coyote
    wiley coyote

    8 years ago on Introduction

    Very nice. Similar to something I tried, but never pursued, using a milk bag to evacuate a 2L pop bottle reservoir and prevent bubbling and loss of pressure once evacuated. It was very successful, but I built a different system instead... also air powered. I found the "lung" worked great, allowing a single air pump to power multiple systems of different lung sizes and elevations. I once had 11 reservoirs of different sizes and elevations on one Hagen 802 pump and they functioned fine, albeit slowly, for days.


    Reply 8 years ago on Introduction

    Thanks Wilie, I never saw your instructabe and the ideas are certainly very similar. I have to acknowledge your "prior art". My earliest version of the lungfish controller thing was totally different. It was a "geyser" in a "diptub" way back in the 1990's in Ireland but the underwater chamber was there strictly to make the geyser effect. It was a 5 gallon plastic container with the bottom cut off and with my "geyser control module" built into the thing through the lid. It was about 4 ft underwater and it shot up a spray or gushes or mist of water depending on how it was set up. It was intended as a mini version of "old faithful" I planned to make it permanently underwater with an adjusting pin to adjust the water hole into the geyser. So you could get spray or mist or pulses of water depending on how easy the water and air got access to the geyser part. But I never did it. Maybe this year? I am building a large hydroponic/aquaponic or convertable soil garden project at the moment, and I hope to integrate some of this into it. Brian


    7 years ago

    you could just put a small hole in the lung. allowing the air to slowly leak into the water. just combine that with the timer.