Backyard Aquaponics
A place to discuss aquaponics

Hey guys,
Thought you might like to hear of my little setup.
Ive used a galvanised metal shelf unit made by Summit with 3 shelves taking 150 kgs each ($50)
On the bottom shelf is a black 50 L recycle bin ($12) containing about ten goldfish ($12), a lovely lilly plant ( which they havent eaten yet!) and some gravel for decoration. There's also a small pond pump ($50) in there with two outflow nozzles.
On the next shelf directly above is another identical recycle tub - approx 30 cm high for optimal bacteria growth and this is full of scoria ( what you guys in Perth call 'pea gravel') as a grow medium. I've used the rough 10ml scoria as this is cheap and has lots of surface area. This of course is one of my grow beds and in it I have planted some bok choy, basil, rocket, parsley and lettuce.
The top shelf also has another grow bed just the same so I'm using a 2:1 ratio for max stocking density as per earthbound's suggestion.

I have attached some clear 15 ml tubing from each of the submersed pump nozzles and these pump the water out of the bottom tub and up into the grow beds. The tubing in each bed is split with a plastic joint from bunnings into two exit points and I have run some 10ml tubing in a spiral pattern over the grow bed surface. The spiral shape works well as the tubing has been sitting on a big reel prior to sale and naturally sits in a spiral shape. This also looks kinda cool and ensures the surface is well covered. like a little spiral maze. In the spaces in between is of course where I have planted my seedlings.
The water flows through the scoria to the bottom of the tub where it drains out of four small holes I drilled through the grow beds and the metal shelves and back into the bottom tub. The top shelf was a bit more tricky as I had to make a bigger hole and then attach more clear tubing that travels back into the bottom tub.
Even those four little holes make quite a bit of noise so I made an ingenious silencer out of some old mesh fabric which I stuck up into the holes with little bits of twisted twine ( you know the plasticky green stuff you use to tie plants to stakes). These little ties sit just inside the holes and keep the mesh from falling off. The mesh square reaches into the top of the tank and the water flows through it in total silence.
On my pump each nozzle has a little valve which controls the flow of water so that the water doesnt get pumped up faster then it can flow back down.
Its a continuous system and when I notice the water flow has reduced a little in the tank I just remove the mesh and shove a nail into the flow holes to clear any bits of debris clogging the drain and then put my silencer back in.
My system is only one month old! Only problem so far is grubs chewing holes into my plants. The fish on the other hand are very happy, the water is pristine and cleaner than any fish tank or pond set up I've ever had and those goldfish are notoriously messy.
Also i innoculated my tank with some lovely bacteria from Joel which comes as part of his 'backyard kit'.
The whole thing is covered by clear vinyl from spotlight ($5 a metre) to stop the rain.
Dont know what I'll do in summer though as the vinyl will surely melt. This unit sits against the wall in my tiny terrace backyard and I plan to make an 8- 10 unit system for under $1000. Quite a bit of veggies with the added control of each unit acting independently, which will help control fish disease spread etc.
Any recommendations for improvement are greatly appreciated.
Sure is fun to be a mad scientist in your own backyard!

That sounds really good dude.

That sounds fantastic Aeon.. And the fact that you've had it running for a month without an algal bloom is good. Though don't be surprised if you do get a bit of one in the coming weeks... And your whole system comes in for under $150 bucks if my calculations where correct..

Great little setup Aeon...Going to set one up this weekend..
Hope to post some pics when done...

PS Hi to all ..great forum...thanks for the book package Joel came via jenny...We are slowly planning our system...

Dean

Hi Dean, Good to see you here....

Please, if you do get a system like Aeons' set up, email me some photos and I'll put them up on the forum, unless you have some webspace where you can upload them yourself...

I hope you'll keep us up to date with your plans...

Aeon, I was just wondering whether your shelving is attached to a wall at all, or if it's free standing..? Does the shelving seem unstable at all with lots of weight up high??

Hi Earthbound,
the shelving unit is galvanised metal and each shelf is meant to handle 150 kgs each -. Its placed against a wall but its sitting within a bricked garden bed that is just wide enough for it to fit in but most of the weight is going back against the wall and we have it standing on the slightest angle on top of a wooden table top we pulled apart and that is sitting on the garden bed so that most of the weight is against the brick wall.. There's alot of weight on the bottom shelf - the fish part -and the bottom shelf sits right on the wooden table top - I really have to send photos dont I?. It appears to be very solid - i cant move it forward off the wall casue its so heavy. There are little holes in the metallic frame against the wall where I could easily drill in some screws and that would make it mighty secure I think, but as this unit is the proto type we didnt want to drill till we were confident that the set up is all ok. We are looking for more wood to run down the rest of the bed so that all the units can sit together equally and we can screw them all together for more structural strength and also affix them to the wall. Originally i kept stuffing around with where to put each shelf and I want to see how tall the plants grow and how much light they are getting before deciding on all that. The top shelf is a bit hight to reach without a ladder but its great to have a true vertical system that uses up the otherwise disused air space around the courtyard. Just bought my first tonne of scoria gravel ( flatmates think its a mild form of pre natal madness) so now I can build the system at my leisure with the scoria sitting underfoot- and it looks good on the ground too! No more concrete nightmare, but shoveling it off the road and into the backyard at 7 in the morning sucked - the things you do for love hey?

Thanks Aeon..... Yep, you'll have to take a pic and send it to me at some stage...... Let everyone see how you have it set up...

Can anyone suggest the min. and max. number of gold fish I can have in my mini system..I have a 50L fish tub and 2 grow beds of 50L...I have set it up as a flood and drain system and will be having a bubbler in it too.

Thanks
Dean

Hi Dean,
Great to see the mini systems taking off!
I've got 10 small ( inch and a half long perhaps?) goldfish in my system which is the same volume as yours.
Earthbound I'm sure will give you the maths to work out the max stocking density - and you can do that as you have two grow beds to filter your tank - which you probably know is the optimum ratio. Now with my system which has been operating for about three months now my vegies are nice and green so they must be getting enough nitrates and the fish water is crystal clear - no algeal blooms yet (but no direct sunshine either) and I feed the fish MUCH more than i would a conventional tank or pond ( a big pinch of flakes every day) and it never dirties the water. By feeding them alot I have managed to save the lilly type plant in the tank from being ravaged and it has grown from a seedling and beggining to cover a sizeable amount of the surface area. I reckon I could probably put another ten in there before it started to affect the pump capacity. My system is continually pumping water ( not flooding and draining) and its more like drip irrigation - very slow. The great thing with a small system is that its so much easier to experiment with factors without ever having a major crisis. Another thing to keep in mind is the wellbeing of the fish. Just because you CAN stock at the highest density doesnt neccesarily make it better for the fish. Think about a freshwater river in nature and how many fish a 50 L area in that river would contain at any moment. Not twenty, thats for sure. The more space the fishies have the much happier they will be and that is good for the system as stress is a major cause for disease in fish. Alot of discussion is given to water volume as far as stocking densities but surface area is very important too as it leads to better natural aeration. Those trendy fish tanks you see that are a deep cylindrical shape with a small surface might fit great in an apartment but its hard to keep the fish happy because they have so little surface area and they can easily suffocate and are more prone to disease.
A good rule is that the tank or pond should ideally never be deeper than the length or width of the surface area. I am assuming you are using recycle type bins? Thay are good as they have a bigger surface area than their depth. I dont want to suggest that those using barrels or other deepish type containers are doing it all wrong - I have seen some great setups on the internet with deep tanks and they are a good option for some situations- especially if they are fitted with extra aeration equipment. I just wanted to make the point that its good to aim for the greatest surface area we can and keep the wellbeing of our fish in mind for the benfit of all the organisms that make up the aquaponic ecosystem.
Cheers,
Aeon.

6kg per 100L is the maximum that you can ever look at, but I never get that high....

Right on Aeon...... Happy fish are much better....

Hey LB,

Hows the eany meany system going? Got any plants in yet or still waiting for a while?

Steve

Going ok steve will post another pic in album showing seedlings..have been cycling the system with some seasol at the moment to give the seedlings a go...getting some goldfish this weekend...planting the seedlings was fun...had to try to remove most of the organic matter as possible from roots..quite easy to pull some stone and plant....thou my hands where well worned afterwards..

Joel, I'm puzzled as to how you arrive at that figure, wouldn't the ratio of bed size to tank size come into the equation.

I ask because I may not have enough room to do the 2 to 1 ratio, and would think that the smaller the ratio, the lower the max stocking rate.

Is there a formula for this ??

Warren

Yep thats dead right Warren... If you have a grow bed to fish tank ratio of 2:1, then you can have a maximum stocking of 6kg per 100L. If you have a grow bed to fish tank ratio of half that, say 1:1, then the maximum stocking density is halved to 3kg per 100L, etc...

But as I said, this is a MAXIMUM stocking density. You have to be pretty sure of your system and your own capabilities before you go this high...