Seeing that I have been accused, by my daughter in the UK, of neglecting my readers, and posting a mere 3 entries in 15 days, I thought I’d better play a bit of catch-up and post something.
We have been up at the new commercial site at Gouna every day for the last three weeks and have made great progress. The idea here was to get two 30m greenhouses up and then decide on the exact configuration.
Here are some action shots of the tunnels going up.
All levels were measured using the trusty old “water-in-a-pipe” method and after everything was up, it measured up perfectly using a spirit level
This is what the frames looked like before we got the plastic on.
The frame is secured by laying a 100mm concrete base at the bottom of a hole for each leg. Then placing the leg (with a cross-pin) onto this slab and then concreting in.
The plastic covering is pulled over the frame…
… and then secured with soil.
The plastic is then secured at each end with clips and the final product looks like this.
We had some very interested spectators with this little fellow following me around for most of the day.
Set out below is a rough sketch of the proposal that I have made to the client and a summary follows.
Two 30m x 9.5m greenhouses.
P1 – P4
4 x 7m diameter mesh ponds, 1.2m high. Capacity 46000L each, holding Tilapia.
Sump. 7M x 3.5m, 2m deep constructed with blocks and then plastered and water- proofed.
G1 – G16
Grow beds consisting of 500mm diameter PVC pipes cut lengthwise, endcapped. Each grow bed eg G1 is two pipes side by side ie. 1M wide and 6m long.
Strawberry towers consisting of 110mm to 150mm PVC pipes notched and suspended from the centre of the greenhouse.
A1 – A4
Aerators consisting of 80w blowers and heavy duty air-stones.
SF1 – SF4
Water cycle #1
The pump pumps water from the sump to the 4 Tilapia ponds
Water flows into a centre standpipe down a 80-100mm drain..
Water passes through solids filters and then to the vegetable greenhouse.
The grow beds are irrigated on a flood and drain system by 20mm valves.
Water drains from the grow beds back into the sump.
This cycle runs for 1 hour on and 1 hours off.
If an individual pump is used for each pond the system will run 1 hour on and 3 hours off per pump.
Water cycle #2
A submersible pump (+- 200w) in the sump, pumps water up.
The water passes through a solids filter.
The strawberry towers are irrigated from above by 20mm valves.
Water drips out of the bottom of the towers into a central drain and the water flows back to the sump.
This cycle runs 1 hour on and two
The system can support almost any vegetable, fruit or flower crop as well as the strawberries grown in the central towers.
I have separated the fish and vegetables into separate greenhouses In this way we can control the two environments throughout the year. Heating/Cooling will be simpler and disease and pest control will be easier to manage.
The sump is housed in the vegetable tunnel, but can be covered and the vertical space also utilised.
I have tried to work as efficiently as possible with energy and excluding heating or lights, the proposed system uses under 2KW of electricity to move and aerate over 180 000 L of water.
Now I’m tired.