Backyard Aquaponics
A place to discuss aquaponics

Hi, am total newbie and would love some feedback and constructive criticism on my design ideas.

I'm thinking a pond approx. 6m long by 1m wide, 30cm deep at one end, slopping to 2m, so I can have a battery solar powered air lift pump (with back up batt) to pump up approx. 30cm to 1st GB (tier system) of vegetables, then gravity feed to 2nd GB of duckweed (half the size of 1st GB) that gravity feeds back to pond.

Added air hoses to aerate pond and GB....10-15mm diameter closed cell polystyrene balls with river gravel on top as media .

Am concerned this is too simple a design... everyone seems to have a lot more components...sumps, solids removal, biofilters, clarifiers etc

For 1st system will just start with goldfish and corn..... haven't heard much about how corn goes in AP, anyone tried it?

Am REALLY looking forward to replies, thanks for listening

Corn grows quite well, just make sure you've got a heavy media. In a dwc, they'll topple over, or with clay balls. But rived gravel will be fine.

With the polystrene balls, I wouldn't put it below the river gravel, I see it becoming a big mess, I'd just stick to the gravel.

Air, have a search on here for air-lifts. They work, but you'll end up using more energy to pump the water then a smaller water pump.

The polystyrene balls will blow all over the backyard on windy days like today, plus they break down into fine powdery stuff , probably toxic, under solar radiation that you don't want your fish (or yourself) to injest.
They will try to float, and the gravel will try to sink, so they will end up mixed, ready to be blown around the yard and broken down by the sun, no matter how hard you try to conceal them initially


With a tank of that shape it will be quite difficult to completely evacuate all the fish poo automatically, it's likely to be a regular manual job - ie not much fun. Much better to have a tank that automatically concentrates the poo near the removal point- pump or SLO.

I'm about to try corn again, but previous attempts have given pasty soft kernels, when grown in gravel grow beds. I'll try some in my AP wicking beds later this year too.

As Colum says above- you're probably better off getting a small water pump for shifting the water- a single 100+W panel, regulator and a decent battery should keep it powered ok. People complain about DC pumps, but I've had no problems with a Waveline DC6000 running full time, and have just bought a Waveline DC 10000 for my other system.
You can buy inexpensive timers to manage your on/off times. The come with a plug-in DC power supply, but no reason you cant run them directly from a battery.

Thanks Colum and Gunagulla, I checked out other posts on airlifts, while some have had success I think I'll go back to the regular pump, although am interested in your thoughts on the geyser pump..... am thinking why have 2 pumps for 2 jobs, when I could have 1 pump for 2 jobs (water transfer/aeration)

Polystyrene balls are also out the window, but have thought of another idea - what do you think? : Polystyrene sheets, with LOTS of 10mm holes, layered on top of each other, with 1cm aerated gaps between them, held down with mesh and traditional media on top? Trying to find something light and cheap. Could you tell me what is the average GB depth?

Gunagulla, what type/shape pond/tank would automatically collect waste near pump?

Sorry if my questions are silly - everyone does AP so differently, it can get a bit confusing....

I think you'll find that much Styrofoam will be very boyant. So it'll push up, and out of anything. Also, the breaking down will be an issue.

Is your issue with cost? 20mm blue metal gravel is very cheap, probably cheaper than the styrofoam you want.

And you want it 30cm deep.

Hehe, got it Styrofoam out! yes, cost and weight... I'm a bit physically challenged and wanted something lighter in case I had to pull it all out to clean/check things..... but at 30cm I guess anything shouldn't be too hard.

Thanks again

Clay balls are lighter. Take up a lot more volume without weighing as much. They are pricier though.

Welcome to the forum Miranda. I'm no expert, but I think general water and sediment flows can be thought of at a glance. Fill different types of tubs, bowls or what every you have on hand, sprinkle a little dirt in them and gently stir. Watch where the sediment goes and ends up after you let it sit. I shaped my pond to coincide with the rock in the yard. It has a natural shape. I planned on all the sediment drop to the lowest point in what is basically a wedge shape bottom where I've placed the SLO (solids lift Outflow). It does, sort of. The issue it turns out is not just the shape, it is also the material used in making the pond. Ours is cement, aka as Stucco as it is known as here in the southwest USA. Even though the cement is coated with three coats of pricey rubberized Herco Koi pond coat, it is still rough enough to collect sediment in any and every depression, because I went with a "natural" finish. It doesn't bother me much. it is my pond and I love it, but if someone were to inherit it, not knowing why I did it that way, they might wonder after needing to run a pool vacuum over the bottom every few weeks, why a smooth and even shape wasn't used. So the bottom line is corners, can make eddies, which in turn collect bits of sediment. Hatcheries sometimes use round tanks and make the water flow from the edges to the center where the drain is. I still saw debris in the bottom of those. There are experts here on hydraulics and I'm certain a perfect shape can be made, on the other hand, they all work to a degree.

2 pumps for 2 jobs is redunancy, is good! If the water pump fails, the air pump will keep the fish alive for much longer than if they had no air. Same applies if the air pump fails- the water circulation will be adding Oxygen to the water, helping to keep the fish alive.

I use round tanks with a slight slope to the centre where aeration takes place, causing an upwards current with water circulating around the tank. The drives the fish poo to the centre, where it is removed via the SLOs.

"I use round tanks with a slight slope to the centre where aeration takes place, causing an upwards current with water circulating around the tank. The drives the fish poo to the centre, where it is removed via the SLOs."
yep, smarts found here

_________________

EPS on the way out, good riddance I say!
http://reneweconomy.com.au/2015/should- ... -ban-59215

HI Boss, yep, I see the smarts, but I can't afford to dig the hole AND buy a tank/other pricey things (only pond liner) (pond has to be underground due to temp. extremes) and thought the 1.5m slope would be enough to move most of the solids to that end, be aerated and pumped up onto large GB, with added bottom feeders in pond and worms in GB, would this get the job done?

Also wondering if anyone is involved with the conservation of Australian fresh water fish? Lots of threatened species but few gov. programs to save them.

Hehe Gunagulla EPS (i'm assuming polystyrene) out water AND aerator in!!

...EPS out, water (pump) AND aerator in!!

You can pick up 2nd hand poly (HDPE) tanks pretty cheaply at auctions - 3000l for $500 or less, also check online auction sites. If going underground a HDPE tank gives you a lot more peace of mind about potential leaks than pond liner.

16 degree slope should move the solids to the deep end so long as a decent flow of water is moving from the shallow end to the deep end and you can somehow concentrate it under the SLO, rather than spread all across the end.

Also, with a relatively shallow section (increases surface area for the volume), temperature fluctuations will be greater, and you need to be careful about stratification if your flow rate isn't large enough.

Thanks Gunaglla, what do you mean by stratification?... and could you tell how important sumps are, I kind of thought the larger sized pond would slow any changes in PH etc, and allow less impact when introducing changes.