Backyard Aquaponics
A place to discuss aquaponics

We are now looking at options for grow beds both in the Tilapia/Veg tunnel as well as at the hatchery. We have been offered some big (500mm diameter) PVC pipes at a good price. They are in 6m lengths. Our idea is to make grow beds by cutting them lengthwise along one wall and then with a bit of heat applied, fold them open to give a 1M wide grow bed made up of 2 x 500mm widths side by side. They will probably be 3m in length. We will use PVC sheets to close the ends and then glue them on with PVC-weld and then finish/seal with marine silcone.

Does this seem feasible? It's quite a lot of money to outlay and I'd hate to get it here and then find out it won't work. Is the 250mm (max) gravel depth OK? Will the drains be easy enough to install?

Any comments would be appreciated.

Sounds more than feasible Synapto.... some posted such a setup not so long ago.... maybe "outback"?

In that case they had also used a large metal ratchet (or worm) type hose clip to give support to the tubing (once cut) to prevent any bowing when fiiled with media and water and subsequent failure of the end pieces...

Make sense??

This may help on the electric fence issues

http://www.sureguard.com.au/electric_fence_solar_103.mv

We used to use a bigger version on the station that had a car battery to store power over night and serviced around 10kms of cattle fence

It was Boris that uses the same idea Synapto....

See Boris's hose clamped PVC half pipes

I just used little ones Plants grow fine in 125mm pipe cut in half - however plants have to be spaced further apart for root space, and you cant flow as much water.

There are windmills that use a rope pump for water that don't need much wind to operate and are pretty low tech. Might be worth looking into. I've also seed wind powered pond aerators though they are probably higher tech.

I think the gate/net idea Might be the way to go. That way you can have one or two gates that remain stationary and you can use something more like a casting net to round the fish into the smaller space.

As to trying to make grow beds inexpensively. Since you have a slope to work with, perhaps you could do earthwork grow beds and then line them. Basically making a trough in the ground (probably have to be across the slope like terraces to get them level enough to work well) and lining it with pond liner. Still would require some plumbing fittings but there are some reasonably priced bulkhead fittings out there. It would require more physical labor to do this way but the cost would be greatly reduced as you would only need liner instead of the stands, and containers.

Good luck!

Thanks guys. Plenty of ideas to think about. Labour isn't a problem. I seem to be very lucky and have a great team. We finished the central slab today of the Tilapia/Veg tunnel. It's 9m x 9m and will hold 4 x 8000L ponds and the sump, plus about 100m of grow beds described earlier. The greenhouse that goes over the top will be 30m x 10m and the slab will be in the middle with the grow beds flowing on both sides. I will start assembling the ponds on Monday. Here is a picture of the finished concrete slab. You can see the 4 central drains where the ponds will be placed.

I was researching building a pond out of cynder blocks the other day and I found a site that builds them commercially using poly sheet plastic and ferro cement that may work for you. Unfortunately I didn't bookmark the site and haven't been able to find it again. It might be a inexpensive way to make some growbeds even if it is just to test them. The contractor said his ponds usually lasted 10 years or better.

Basically what they were doing was digging out the shape as you would normally for a pond, then installing a couple layers of clear or black poly plastic sheeting (I believe they were using 6mm)then applying a 2-4 inch layer of cement mortar with chicken wire centered in it. Plumbing piping was all installed through the poly sheeting and sealed with silicone at the plastic level. No coatings were used on the cement although it was allowed to cure in water for a couple weeks before it was drained and fish were introduced. The plastic makes the pond or trough waterproof but the ferro cement protects the thinner plastic from puncture and UV degradation.

If I find the site again I will add a link as it goes into more detail than the above.

I need to build a turtle pond for a new animal addition to our household so I may use this technique to try it out.

Robert
Central Texas

I have a colleague who is building a Dusky Kob (Mulloway) facility near East London (South Africa) who is using cement blocks.

This is what they look like and the profiles they use to make up the pond.

how many courses of the blocks make up each tank?

Not sure, but I think about 10 courses. Here's some more images, see if you can make it out.

Sman u continue to be an inspiration. Hope u haven't seen 'Gorillas in the Mist.'
With olive trees, a mature tree will give u about a litre of oil. Hardly worth it on a small scale. If u want the olives themselves for the restaurant, a different story. With a 5 year lease, I would be going for maximum produce, leafy greens, herbs to onsell etc.
I look fwd to ur 3 photos in the 'large system pic gallery!'

TT, the olive trees I've got are oil varieties and just for a bit of ambiance and just to see what they do in AP I've put one in my home AP system to observe. Putting them in containers at least I can take them with me at the end of the lease. Who know's I may even buy this little piece of land if the farmer agrees. On the other hand I may be in Oz or NZ before then if our local "situation" deteriorates any further. Leafy greens, herbs, basil, chilli and tomatoes are probably the way I'll go at this site.

is that the same farm as the strange man photo?

Yep !!