Backyard Aquaponics
A place to discuss aquaponics

Here is pic of a proposed "Tank In Tank" design. I came up with this trying to find something simple, aesthetically pleasing and compact. One pump, one valve, one timer.

The idea is to have a 2m diameter 300mm high tank, and then a 1m high 1m dia tank inside. Pump from the outer tank into the inner the water overflows through small holes with small pipes, through various level of plastic pot beds back into the outer tank. The idea is the pump always runs but the valve opens over to divert the flow straight back to outer tank to allow the beds to drain.


Excuse my Paint skills or lack thereof, and choice of grey that is hard to read.

The drains out of the beds would be sized so the gradually fill to overflow, and then the valve timing so once the beds overflow it goes to period of draining.

The idea would be to have larger fish in the outer tank, and smaller feeder fish in the inner tank.

Tell me what you think. Problems I see:
1) Subject to settling of stuff in the inner tank as the is no agitation in the lower part.
2) Would be outside so need to maintain level after rain.

My login isn't working. the above should be Author : b2barker (AKA Gavin). Evil internets

Problemn solved after re-reg. All is good

Cool idea Gav, I'm going to have to read back through it again, and have a closer look at the picture to comprehend it completely.

So is the plan to have the drain valve switching on and off on a timer?

You could almost have the middle taller one at about 1.5 m, getting more plant pots on the way down... A bit like a tall water feature such as you see nowadays, water flowing down some bit of plastic made to look like a rocksurface..

If the beds/pots were very free draining with gravel in them, then there wouldn't be much need for a flood and drain action, you could have it flow continuously.

The stagnant water in the base of the taller pot can be moved a little by having a tee off the pump line before the fountain bit, this would run a pipe to the bottom of the tall tank, just pushing water slowly to stir it up.

I like the idea, you could make this all look very nice...

Yep, the valve would be off a timer, and only as you say if you wanted a flood/drain effect. Without flood/drain, I could change the valve to a 2-way that either recirc into the bottom of the inner tank (which would still overflow into the pots) or switch to the sprinkler head,

1.5m would rule out viewing into the inner tank, and make it hard to catch the little fishy's.

I just saw containment tanks at this site:
[img]http://www.plastic-mart.com/db_images_th/ab605d03898a9c6d325080fc93c15580[img]

http://www.plastic-mart.com/class.php?cat=21

Just wondering what would happen when the top is cut off the tank and it is filled with water? Anyone done that?

Lee
Still wondering how I ended up in the wrong OZ

Maybe you could solve both these problems by using a venturi standpipe-siphon arrangement like VB.... that lifts the solids off the bottom.

An overflow through the standpipe when it rains would take care of the problem for the top tank.... you'd just need an overflow from the bottom tank.

Hey Lee:

Check it out:
http://backyardaquaponics.com/forum/vie ... 5971#35971

Hehe I was very keen on that idea 18 months ago. I still don't have an AP setup In a few months I may finish my house extensions and revisit my cunning plans
Here the google sketchup version which I put in some other thread way back when.

I think it would look and work great.

Just two minor issues i see which you have probably already taken into account...
The shallowness would make the fish vulnerable to predation (easily solved)
Depending on how tall/long your arms are the feeders in the inner tank may be abit of a challenge to net (again easily solved with a step/brick in the tank or a fish release valve, etc)

Hey B2B Sketchup King:
That's a very nice aesthetic system, it would be fun to see the fish like that.

It might be tweaked to allow more fish load, through incorporating more gravel volume and making sure the solids get filtered out. Maybe the outer ring would be grow bed space, to hit the 2:1 target.

Hey Rope, that quote/comment was made over 18 months ago....hehehehe - oh sorry, didn't mean that :snigger:

Couldn't help myself B2B - had to have a dig also