Aquaponics 101 – Don’t try this at home.

Right. Now for something completely different. How to turn a small IBC aquaponic (AP) system into an oyster display tank. You can’t be serious? Well I am, so here goes.

Some time back I showed you how to build a small home AP system using an IBC.  This week we decided to design and build an oyster display tank to stock these succulent molluscs in our restaurant, the world-famous Old Gaol Restaurant at the museum complex in Knysna, South Africa, for the annual Knysna Oyster Festival.

Let’s start by listing the differences between the two systems.

  • The AP system uses fresh water, the oyster tank, saltwater.
  • The AP system has plants, the oyster tank has none.
  • The AP system stocks fish, the oyster tank, mmm, oysters.
  • The fish need food, the oysters don’t, as they are being purged.

But there are also many similarities.

  • Both systems need to remove harmful Ammonia.
  • Both systems thrive on elevated dissolved oxygen (DO) levels.
  • Stocking densities for the volume of water is important.
  • Both species have specific temperature requirements.

It made perfect sense to thus diversify somewhat, given the low temperatures that were causing such problems with the Tilapia.   Oysters thrive on temperatures in the 8-16 deg range, exactly what will seriously compromise or even kill, Tilapia.

So, how did we go about it? Well firstly we netted the remaining fish and moved them to the big “Koi” pond to see how many will survive outdoors through the Winter. Then we emptied the growbed, replanting the vegetables in other growbeds and in soil. The tank and growbed then had to be thoroughly washed and sterilised. I use a chlorine and hot water mix to sterilize tanks, as it kills any bacteria and other uglies, and gases off after a few hours if left in the sun.

I used the existing submersible pump, but added a venturi pipe to suck in some air and provide some great aeration in the form of fine bubbles from the spraybars.

The flood and drain cycle of the AP system would work just fine for an experimental “tidal” system that I had been planning for some time. Here is what the tank looked like after rigging up.

oyster_tank1

What you see at the bottom of the old growbed is coral, which I am hoping will provide some bio-filtration. The oysters are going to be placed on top of this coral and I estimate that I will be able to stock 100-200 medium oysters for the given volume of water (about 300L).

The way the system works (which I am hoping will fool the oyster into thinking it is back in it’s natural environment) is that it will flood the container up to the standpipe for about a half an hour, all the time bubbling fine sprays of air into the water. Then the pump will go off and it will drain and then lie dry for 15 minutes. Then the procedure will be repeated. High tide, low tide, high tide, low tide.

Here is a shot of the spraybars in action. Note the fine bubbles.

oxygen2

The drain into the container also adds more oxygen by the waterfall effect of the falling water.

oysterdrain

The venturi was just achieved by placing a t-piece into the suction line and letting it suck some air from above the surface. This took some tweaking, but it seems to work just fine now. Here is what it looks like.

P200609_10.00[02]

We have now placed 6 medium oysters in the system as “crash test dummies” and will monitor their condition until the Child Bride and I stock the system next Thursday. I’ll keep you posted.

Cheers

Synaptoman

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12 Responses

  1. Hi Great site. I stumbled across it a while ago while trying to see if anyone was using chickens in Aquaponics like i was at the time. How is that part of things going ? We had our chicken system going for nearly 2 years , no fish just chickens(actually some small native fish for Mozzie control) and it Pumped ! Keep up the good work
    PS if you want the rundown on our system drop me a line.

    Cheers Tim

    • Hi Tim,

      Thanks for your comment. The chicken exercise was a moderate success, however the nutrients supplied by the chickens and the impressive fish growth was unfortunately offset by clogging and fouling (excuse the pun) problems. If we could find a way of eliminating the feathers and chicken feed spilling issues I think we’d be onto a winner. Yes, I’d be very interested in a rundown of your system. I’ll email you privately.

      Cheers

      Synaptoman

  2. Hi,
    My name is Mike and I live in British Columbia, Canada. I found your article about the oyster tank just great. What happened to the 6 oysters you tried. Did your experiment worked out?

    Thanks,
    Mike…

    • Hi Mike,

      The 6 oysters survived and the tank is now fully operational. We have moved about 500 oysters through it so far without need for a water change. The only concern is that the temperatures are going up here in the southern hemisphere and I need to consider a cooling option soon.

      Regards

      Synaptoman

      • How fast do the oysters mature? Did the rising temp affect the oysters? Do you think you could also grow seaweed with the oysters? Did you use 100% saltwater or did you do a brackish water mix? How do you start an oyster from it’s first stages of life?

  3. Can oysters actually be cultivated in a small indoor setup in a home environment? It sounds like you’re getting them from somewhere else, not actually cultivating them, but since it sounds like you know about oysters, I thought I’d ask you. I’m currently setting up small ebb and flow hydroponic systems to grow my own vegetables and love the idea of aquaponics. Only problem–I don’t like fish, but I love oysters. If I could raise fresh-water oysters and vegetables in a symbiotic aquaponic arrangement, that would be fantastic!

    • Hi Ken,

      The layout described in that article is purely a holding/purging tank. I don’t know of oysters being grown economically in a closed system like this. I also don’t think that fresh water oysters would fare any better as you would be unable to feed them the special algaes and micro plankton that they need to survive and grow.

      • Do you think it could be done non-economically? Seriously! I love shellfish but live in land-locked Colorado. Could I perhaps grow my own special algae and plankton? Even if it costs a bit as to become non-economical, the benefit of fresh sea food in my diet might make it worthwhile.

  4. most shellfish are marine animals. i havent seen any saltwater aquaponic systems yet

  5. Absolutely love your stuff man. Im about to buy your book. I also just set up a new system to test supplementing P and K by using pH up and down equally

  6. Sorry forgot to ask my question, my mind is a little blurry right now. I’ve been reading this all day…

    Are those just valves you use on your spray bars?

    I’ve been modifying my pumps for venturis and cant get anything like you have! I attach a cutout of screen door material over my impeller to shred the air coming in through the intake into tiny bubbles and even compared to my 700 pump the bubble action coming out of yours is insane!

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