Backyard Aquaponics
A place to discuss aquaponics

I'm just about ready to start my first AP setup. After a fair bit of research and a good chat with EllKayBee, I'm thinking about placing a 500L FT under my back deck (which is currently wasted space), and placing the GBs on the deck above (about another 4-5 ft above). This will This will be flood and drain with gravity feed back to the FT, using an electronic timer on the pump. This will allow me to use up space currently going to waste, and avoid having to run electricity to the back yard. It would also make the veges/herbs very accessible (as a bonus only).

I need to know:

• what pump would be suitable, especially given the height difference.
• what size GB - I was thinking about using a bath tub I already have and getting another, but weight/aesthetics would be an issue
• weight could be a problem using gravel - is expanded clay much lighter (or is there any other option)

This setup is basically a "proof of concept" and if successful, would probably become my nursery down the track, with me building a proper growhouse with a more substantial setup (2000-5000L) in the backyard a bit later.

Don't know how strong your deck is Ryan...

But consider a m3 fo gravel weighs about 1000kg and 1000ltr of water weighs the same...

Yep expanded clay is lots lighter..... .... but not as cheap as gravel....

Yeh, too heavy for the back deck, hence the question about expanded clay. with a 500L Ft, what size GB should I be looking at?

between 500 - 1000l

Ryan, you can start off with just the one bath tub and keep adding to it - normally we work on 2:1 ratio of GB to FT will support 6kg of fish weight.

Example:
500 litres of fish water would support 30kg of fish
1,000 litres of GB media also supports 30kg of fish

If one is less, then calculate to the smaller volume (250 litre of bath tub supports 7.5kg of fish )

Normal plate size fish is around 500 grams, so from all those figures, you can work out a reasonable stocking density.

My system you saw today has a 1:1 GB/FT ratio and you saw the sizes of the fish I harvested and my stocking density

Hmmm, definitely food for thought.

I think I'll just go to the trouble of running electricity to the back yard, and keep it all down there. A shame though, considering the space under the deck is going to waste...