Backyard Aquaponics
A place to discuss aquaponics

A quick run through on my system


Main tank – 1,800 litres round galvanised tank (aquaplated)
Sump – two 400 litre in-ground rectangular tanks, coupled with 40mm siphon pipe (hold ~700l)
Grow Beds – six troughs measuring 1780 * 1360 * 290mm (hold ~460l of gravel)
Pump – 3,000lph submersible

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Note - the wet ground DOES NOT denote leaking tanks/pipes...we have finally had a lot of rain and all the ground got very wet
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Pic 1
Water is pumped from sump tank to main tank via 25mm pvc pipe, the 32mm pipe is the return from the GBs

Pic 2
The 25 mm pipe is angled so that the water swirls around the tank, this causes solids to be moved towards the centre of the tank and exit with the water flow.
The centre vertical pipe is 90mm diameter – the slits are a safety feature so that if water flow from below is blocked then it will flow through the slits and down the stand pipe. Cut outs (crenellations) are cut in the bottom of the 90mm pipe to allow water to flow from the bottom of the tank into the pipe
A 50mm pipe stand pipe is inside the 90mm pipe, the height of this pipe is the height that the water is showing in Pic 2, water flows up the 90mm pipe and then down the 50 mm pipe, through connectors on the bottom of the tank to the GBs; this is called a venturi drain, the water level in the main tank remains constant at all times (this is the beauty of this type of drain).

Pic 3
50mm pipe from under the main tank going to the black box configuration which then supplies water to the selected GB via the actuators and flaps (the other piping is the return water pipes from the GBs flowing back to the sump tank)

Pic 4
The larger 50mm pipes connected to all the black boxes, the smaller 32mm piping is spreading the water along the GB length, large holes are drilled in the underside of the pipe and a 90 degree elbow to the end, this is to keep the top layer of gravel as dry as possible to minimise algae growth

Pic 5 The black box
The centre connector is water inflow from the main tank
The outlet on the left (with flap) is identical to 5 of the GBs, the flap is normally closed unless the GB is to be flooded, water level can be seen to be about half way up the closed flap.
The outlet on the right (no flap) is higher than all other flaps, when all flaps are closed water level rises and flows into the right hand GB (this is done so that if all flaps are closed incorrectly then the black boxes won’t fill and overflow – safety feature MkIII )

Pic 6 Water Level Sensor MkVII (I think )
WLS – small paint bottle connected to a piece of red Perspex, the bottom piece is hinged so that as the water rises and floats the bottle – the bottom plate rises, which in turn makes contact with the two S/S bolts and a circuit is made to activate the flap actuators.
The flap at the bottom of the drain pipe regulates the GB outflow, normally these flaps are open and work in reverse to the black box flaps – when In flap is opened, then Out flap is closed to flood the GB.

Overflow pipe - safety feature (another one) if flap doesn't open the GB will flood then water will flow down drain pipe instead of over the GB sides

Pic 7 The wiring
Terminal wiring block
Power Relay
Main actuator (connected to Out Flap)
Slave actuator is the one mounted on the black boxes, these are reversed wired so that when the main actuator is up then the slave is down (open/closed)

Terminal Block
Top left to right
1 & 2 (green wires) connect to the S/S bolts on the WLS
3 & 4 – earth/12vdc from power supply in garage
5 – connects to next GB power relay, when the WLS activates on GB3 and the Out Flap opens, it also activates power relay on GB4 which closes GB4 Out Flap (opens GB4 In Flap)
6 – connected from previous WLS (GB2), which closes Out Flap on GB3...and so it circulates, filling one bed at a time

Bottom left to right
3 – supplies a common to pin 2, through the WLS then back to pin 5, black wire runs to power relay
4 – 12vdc power to relay and actuator
5 – output from power relay to activate next GB
6 – input from previous relay
Data sheet on the power door lock diagram can be found here:
Data Sheet

Very good excellent description sonny now move to the top of the class[ thanks les now every body has to do one]

...especially vb's and Steve's

I'm impressed !

Where are the actuators from?

No don't tell me, I haven't even got a simple system working yet!

Sorry about that Scot.t.t.t.y, should have put it in
2 door power lock kits

'Tis a thing of bewty you have there

Thanks Ell all nice and clear..

I got to ask, can you replicate it?
and what would the cost be?
Not so much the containment but the bit's and pieces?
C1

You can't replicate perfection C1, it is priceless

Did a costing once, think it worked out to <$50/growbed, big cost was the door actuator kits @ $30 ea

12v power supply was ~$80 from memory, so that bumps it up by another $15/GB

Compare that with zero pressure solenoid valves (50mm) quoted at ~$500 each plus a power supply

Ok, thats excellent Les.
Now you just have to build one for each of us!!!!
I am putting my order in now!!!

How long do you think we will have to wait

I am going to pick up a slave actuator from jaycar and see if I can drive it directly without the relay unit. Relays are as cheap as any thing (~$2) so you can make a single relay board to control the whole lot, so all the sensors can be low current. Plus you can cut down on wiring. So for $30 you could get three actuators.

Yep - you can do it with slaves only, I liked the idea of having all the connectors and wiring loom all supplied (one less area I needed to fault find on ).

Interested in how it goes Tim.

The actuators are near on bullet proof and have a lot of power, they are pulling/pushing a solid flap through water very quickly