Backyard Aquaponics
A place to discuss aquaponics

I think i have mentioned this before Ballarat trout farm[running since 1870] have about 38 races and ponds in there races theres just a 1 1/2 pipe flowing in one end then flowing through strainers [to stop fish migrating ] they do not remove solids well once a year and theres up to 40 cm junk in the bottom from these the water goes to other ponds to the second last one where the big ones are then to the last where theres a paddle wheel they top up from a bore running 1 1/2 pipe 12 hrs a day they have millions of fish If thats not intenseve farming what is!

DanD, are you looking at doing this commercially? If so why aren't you considering the friendlies Hawaii commercial course or DIY manual? $900US ain't cheap, but in a commercial situation if it saves you from one mistake or trial and error, it'll pay for itself.

It would seem to me that friendlies are walking the talk and it could well be worth your while jumping on a plane and checking their operation out. By all reports they are intensively producing Tilapia using a modified UVI system which is not dissimilar to the one earthbound has set up in WA.

There are a lot of other things to consider beside just a system that is designed to keep the fish happy. One of the major time users/costs and therefore an important element in design , is the fish grading. The system needs to take into account the human element , a super efficient tank 300 metres deep that requires scuba gear to do the grading want work. I forgotten the company name ,, but they had bladder bottomed tanks , fill with air , fish get gently pushed out , graded and return to next tanks.
It is something that needs to be taken into account in the design phase.

No, its not a commercial operation. I simply have limited space and want to grow enough fish to feed 4 families in a small space. This is more of a "retirement" option for me and a way to reduce my needed income by 25%.

I am in the process of building a grid tied generator that will back feed my meter to cancel my electric bill and provide all the backup power I require to run AP in the even of power failure.

I would like to reach stocking densities that allow me to grow something like 1500 pounds of fish per year (680 KG). I want to get there without the use of oxygen because I see oxygen concentrators as to complex of a device that I might not be able to repair myself. EBs commercial system seems to have a stocking density of .423 pounds per gallon. At that density I could grow enough fish for everyone in our family to have a fish every day in the water volume I already have! I cant afford to buy anything commercial so I have to build it my self.

One thing is for sure, exchanging water only once per hour on an intermittent basis is not sufficient for fish health even at low stock densities.

If energy is not an issue for you, maybe you could use a motor to run a hand-made paddlewheel or harness the wind for a wind mill to churn the water and add oxygen

I have considered that, but with 12 psi almost all the oxygen in the air is dissolved into the water. I see no reason to not use the counter current oxygen injector.

sorry, i don't know the context of this comment as i only skimmed the page. you have running water, and running water can always turn a paddlewheel for free. more surface area for bacteria too.