Backyard Aquaponics
A place to discuss aquaponics

I bet I can get pumice gravel or something similar - good idea. My hands are already ugly - it won't hurt.

Pea gravel is pretty darned smooth around here and works fine. Main things we look for are

1) air space so roots can breath and water can flow and so things don't get anaerobic as soon as some fish muck gets pumped in. This is one reason most (but not all) folks use size-graded gravel and wash off the sand and mud.

2) lots of surface area for bacteria. Any sand or gravel works fine for this.

I'm sure river gravel could work fine if you get decent stuff. I would worry about using the sand.

There is almost certainly pea gravel in our river - we just need to sifters to get it - one to remove the large stuff - another to remove the smaller stuff (sand) - and if we get it from the river, we can assume it is washed.

I was reading a thread about powerloss and backup systems. I have a rather large pond with a monk (think a 2 meter spillway) - if I were to build the system next to the monk, I can place a waterwheel in the monk which will power a mechanical pump. We have a good flow of 6 inches or more year round - with a 2 meter drop, I suspect that will be more than enough. Then a automatic siphon completes the equation. Too many fish - through them in the pond (or eat them of course) too few, get some from the pond.

I see no reason that I can make this thing without needing any power - and of course, not needing any backup system.

There are lots of great designs for hydro powered pumps. You can also make a mechanical aerator.

Yep - and I can actually buy them off the shelf here.

Hmmm, one issue I was thinking about - though the pond is tempting - I have to walk down to it about 100 meters. This is of course very good for me - but perhaps not so good for maintaining it.

But, on the flip side, if it is next to the pond, the pond is stocked with guapote (I think they are called peacock bass) and Pinto - I can stash my fishing pole and act like I am review the system while fishing - some of the guapote are over a kilo aready and heading to 4 to 5 kilos in the future... Lots of fun.

Decisions, decisions.... I know my wife will say build it below so I will get the excercise walking up and down that hill!