Backyard Aquaponics
A place to discuss aquaponics

Just playing with a designed just a concept at the moment haven’t fully thought it out yet wanted peoples opinion about it,
basics is, using 2 ibc fish tanks, that flow to a bio filter in a drum which flows to 4 cut blue barrels as media beds which flow to 3 dwc beds with flow rafts.
first two IBC will continuous flow to the third tank, basic solids catcher on the pipe, third tank will flow in to barrel filter (plan for gravity but depends how high I end up putting things if its to low ill pump from tank 3 to filter) filter will continues flow to 4 media beds which will flow to 2 of the dwc beds that will be about 3.3m long by about 1 meter these bed will flow in to the 3rd dwc bed which would then pump to top of tanks. Fish stock rate would start low, 50 barra spread over the 3 tanks, after a few months fish would be moved to 2 tanks and the third tank used for new fingerlings,

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Don't drink water, fish poop in it

What type of bio-filter media and what volume?

Blue drums cut in half, filled with exp' clay and with a 50mm dry layer at the top, will safely support a maximum of 3 Barra through to plate size of 500gm.

Also, cut vertically, each 1/2 drum grow bed will provide less bio filtration than if cut horizontally. They will also require framework to stop their base and sides from bowing, whereas cut horizontally they wont require any.

You will need an adequate amount of fish to provide the nutrients for these, and the fish numbers in the system will be dictated by the amount of bio-filtration, ie: wet gravel in media beds or a bio-filter. Too much floating raft area in ratio to bio-filtration, and therefore fish, will result in deficiencies.

Third tank?... Is this a sump tank after the 2 IBC FT's, but prior to the bio-filter?

So two pumps, is that correct?... I definitely would not recommend running two pumps. That would be overcomplicating something that, with a bit of forethought, could otherwise be achieved with a single pump. It would also create a huge potential fail point.

As I think Scotty may have covered on another of your threads, your stocking rate would be dependent on the amount of bio-filtration in the system, ie: wet gravel in GB's and/or bio-filtration media in your bio-filter. So you would need and idea of the total bio-filtration capacity of the system before deciding on your fish numbers.

You would also need to bear in mind, with Barra, even in well aerated water with good mechanical filtration, ideally you would want no more than 30 plate sized (500gm) fish in each 1000L FT.

Being in the NW, I wouldn't recommend pipe systems/components of any description. They will very effectively transfer heat to your system water. I would be more inclined to build the system entirely out of IBC's, with multiple media filled beds and maybe a floating raft (DWC) bed or 2, but ensure the exp' clay depth is at least 300mm in the media beds, and the same with the water depth in the DWC. I also wouldn't be tempted to use blue metal as a GB media up there.

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Mr Damage - a.k.a: Yabbies
Owner at Perth Aquaponics - Aquaponic Consultant & Trainer
Trade certified Horticulturist & Cert IV TAE

Thanks for the response,
not 100% sure on the bio filter yet,
I like the idea of cutting the barrel horizontal, iv used vertically cut ones before, more grow but less filtrations, and yeah the extra support is a pain.
with the stocking rates would be 50 over 3 tanks, then 25 (or whats left of the 50 2-3months in I have seen edible barra in 3 months up here) in 2 tanks and 50 fingerlings in one,
all 3 tanks would be before biofilter.
theres a lot of debate around bio filters and the need of biofilters in dwc, I have ran dwc before with out a biofilter and just a solid catcher but this was a pretty small system but it makes me wonder, however I will still have a biofilter though. Iv searched a bit and have read different stuff on dwc surface space as the biofilter and the amount its worth compared to media grow beds, I have seen a few ratios but all seem to high.
iv used 2 pumps before it is bit of a nightmare but due to the space it might not be avoidable but I do hope to only use one.
iv ued pipe systems before and they work fine in the right spot, my current spot isn’t the right spot so ibc or dwc is the way, I was looking at 500 deep for dwc. Also with any pipes that I am able to I cover or burry as much as possible not only does the sun heat the water it greatly agers the pipes haha

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Don't drink water, fish poop in it

One suggestion given to me was to create more surface in the dwc bed it self, using shade cloth or bio balls in a pocket attached to the bottom of the bed, this may work in regards to making more bacterial area but it may slow the flow to much

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Don't drink water, fish poop in it