Aquaponics?

[Tiny Allotment]

As some of you may know I recently built a Geodesic Dome Greenhouse to house an aquaponic system.

For those of you who do not know what aquaponics is it is a technique for growing both vegetables and fresh water fish in a symbiotic closed loop system.

Fish excrete ammonia through their gills and in their urine. Ammonia is poisonous to both plants and fish but two types nitrifying bacteria that naturally builds up in the system converts the ammonia first into nitrites and then into nitrates which the plants take up as food. The water returning to the fish tanks is much cleaner than when it left and so the cycle continues.

You loose very little water with an aquaponics system and the only other major input into the system is fish food but there are lots of ways you can reduce his as well.

Is there anyone on the forum that practices aquaponics?

paul

[Tiny Allotment]

We were going to use IBC containers to build to the aquaponics system but I have found it quite difficult to find any at a reasonable price so we have decided to build the sump tank, fish tank and grow beds from scratch and then line them with pond liner.

This has many advantages. First, the sump tank is going flush with the ground and it would have a long job to dig a metre cube hole in the ground we have at the allotment. Plus we can dig the holes for the tanks any shape we like so we can make thee whole system more attractive and natural looking instead of the normal science experiment look. Also, we would have to start taking panels out of the dome in order to get an IBC in because it wont fit through the door.

We are going to be building what is called a CHIFT PIST aquaponics system. CHIFT PIST stands for Constant Height In Fish Tank, Pump In Sump Tank. This means that if the pumps stop working or a pipe comes off and pumps all the water out of the system there is no way that the fish tank can be accidentally drained.

The pump in the sump tank constantly pumps water into the fish tank. The fish tank overflows into the grow beds which flood and then drain via a syphon back into the sump tank.

We are going to be having some growbeds with clay pebbles as a growing media which will also act as a bio filter which will filter out solid waste and some growbeds with no media with the plant roots just growing in deep water.

I will probably begin digging the sump tank this weekend if anyone fancies giving me a hand

Paul

[Bigmallly]

How do you plan to power the pumps Tiny?

[Tiny Allotment]

We will be powering the whole thing from solar panels and later a small wind generator. We will have a small battery bank so the pump can run 24/7.

I am looking for a 12 volt pump at thee moment. It would need to be about 1000 litres per hour and a metre head. If not we will use 240 volt pump and an inverter.

One of my projects is going to be a DIY heliotrope to track the sun and we are going to experiment with adding angled mirrors and active cooling of the panels

As I say "I like a project"

paul

[Bigmallly]

Sounds like you've thoroughly thought it through.

[Tiny Allotment]

Thinking about it is the easy bit. It never works out exactly how you think it will but it is always fun building stuff and getting it to work.

Things like the sun tracking system you don't really need but when people see it working they are so excited about it it makes the effort worth it.

paul

[PyreneesPlot]

Sounds very interesting.
When we first moved out here we were off grid using solar and batteries ( not windy enough for a turbine) and had a ten day spell with not enough solar to charge the batteries. Do you have a back up if you have a prolonged grey spell? Our usage was ltd to lights only at the end and boy were we glad to see the sun!

[Tiny Allotment]

I do have a couple of portable generators which I can take up the the allotment to top up the batteries or I could use the car to charge the batteries.

maybe a bicycle powered battery charger would be a good idea.

Paul

[RedThorn]

It's far harder to stabilise and settle down than you may think as early on you have small plants and do not pull the nitrites and nitrates out the water fast enough, later the roots can block the water flow through the blown clay

For the system to be truly effective, you need plants round the year, yes the fish slow down, they do not stop.
If you heat the water and provide artificial light, it'll improve efficiency not not cost....

Just some food for thought

All the best

[Tiny Allotment]

Thanks RedThorn

Yes cycling the system can be tricky as you say. I have been reading about aquaponics for about 6 years now but because we are of no fixed abode I have never had anywhere stable enough to build a system before. I am a member of a couple of aquaponics forums so I have access to a wealth of knowledge on the subject but I am still anticipating problems along the way but I think it will be worth it in the end.

Have you built an aquaponics system yourself?

Paul

[RedThorn]

I've dabbled and experimented a bit but work hours at the moment are not conducive....
The results though do look promising.... So here's to retirement one day

[Tiny Allotment]

We have recently started work on our aquaponic system. I have buried an IBC in the ground for the fish tank (later to become the sump tank of a CHIFT PIST system)

I have filled the fish tank with water and I am now gathering the plumbing parts to build the bell siphon.

To start with we are going to use a bilge pump just to get the system cycling so I can test the siphon but later we are going to investigate and experiment with an air lift pump.

We have a lot of exciting things happening in the dome this year so i will try to keep posting what we are up to as long as people find it interesting,

Paul

[Tiny Allotment]

I have been experimenting with a U siphon and initial tests are promising. I have done some alterations since this video and it is working even better now.

Just need to set up the solar system to power the pump and we should be good to go

Paul