Gravity supply or return system, which is best

[Dan Ponton]

In my up and coming system, is it better to:

1. Have the beds a little higher than the tanks and pump the water from the sump up into a header, down through the beds and down into the tanks?

2. Have the fish tanks higher than the beds and gravity feeds the beds and down into a sump then pump the water into the fish tank?

Any suggestions

[Tony Gilliam]

Dan, My system is in the design stage as well. I haven't seen any systems yet where the flow goes from the fish to the plants then to the sump. It is my understanding that, the ammonia is brokedown and converted in the sump, then absorbed by the plants before it goes back to the fish.

I'm not really sure that the flow path is really important but i would think that the cycle time would have to be increased if the flow is going to the fish first.

[Dan Ponton]

OK... so gravity from fish tank through the filters and pumped to the raft beds and gravity back to the ibc tank.

I am also thinking to use a second ibc tank for a shrimp tank and filter setup

Tony Gilliam said:

Dan, My system is in the design stage as well. I haven't seen any systems yet where the flow goes from the fish to the plants then to the sump. It is my understanding that, the ammonia is brokedown and converted in the sump, then absorbed by the plants before it goes back to the fish.

I'm not really sure that the flow path is really important but i would think that the cycle time would have to be increased if the flow is going to the fish first.

[Chris Cates]

Actually the ammonia is broken down by the bacteria that has colonized any surfaces in the system, including the media in the grow beds.  The sump is usually used as a buffer to keep the water level in the fish tank from fluctuating too much and stressing the fish.  In my case I run two pumps from the sump.  1 feeding the grow beds which auto-siphon back to the sump, and one feeding the fish tank which is on a constant flood setup over flowing back to the sump.

Tony Gilliam said:

Dan, My system is in the design stage as well. I haven't seen any systems yet where the flow goes from the fish to the plants then to the sump. It is my understanding that, the ammonia is brokedown and converted in the sump, then absorbed by the plants before it goes back to the fish.

I'm not really sure that the flow path is really important but i would think that the cycle time would have to be increased if the flow is going to the fish first.

[TCLynx]

Here is a link with some diagrams that might help you get your head around some of the different options.

2011 Aquaponics Plumbing Class