Backyard Aquaponics
A place to discuss aquaponics

I'm looking to build my first aquaponics system and need some advice. So far my experience is in simply growing a lettuce over an existing fish tank and I need to scale this up. One advantage we have is the fish are already here.

For the scaled up fish tank the house is surrounded by a moat which is stocked full of carp, roach, catfish, moorhens and ducks among others. We have never really measured it properly but I'd estimate somewhere in the region of 2500 cubic meters or 100,000 cubic feet of water.

We probably have well over 3000 fish in the moat. Most the fish seem to be small roach around 10-15cm, there are at least 300 carp over 30cm long with some much larger and we caught a 1.2m catfish in there too. The fish have been there longer than us so I don't know what else is in there really.

Part of the garden is on the bank of the moat about 50cm above water level and there is an area of shallow reeds in front of it. We plan on using an area on the bank to start a small grow bed with the aim of scaling it up and putting a grow bed on stilts in the shallows if it works well. The first tester system will be probably around 1m x 1m grow bed - there is space to expand this quite a bit if things go well.

Initially it will be a lettuce and herb garden. Moving forwards we would like to add tomatoes if possible and other plants. The area is south facing so gets the sun all day.

I will add photos of the area as soon as possible.



On to the questions:

- I'm looking for a low cost solution for the grow bed and the plumbing to start with. Suppose the growbed is 1m x 1m x 30cm deep how big a pump will we need? All the advise I find online bases pump size on the volume of the fishstock - for us we just need to water the plants really as the fish are already there. Can we do this with just a small $20 pump? What is the cheapest way to set up the plumbing? I was thinking a flood and drain system with a bell and syphon might be best here but I'm not really sure.


- If this works well and we scale it up I was hoping it would help clean the moat. Currently it's very murky and has about 1m of sludge and slime at the bottom. How many grow beds and plants would we need to filter the water and clean the moat, and how long would it take? Is this the best way to filter the water? (Would it even work at all?) We can't get a digger in the moat because it could damage the base of it and drain the lot so we're looking for a way to filter the water and aquaponics seems to me like a good fit. There are fresh water mussels and crayfish in there as well as all the fish but currently the water is too dirty for us to eat any of it.


Any help you can provide would be much appreciated

Hi Hugh
Couple of thoughts.
Consider a poly tunnel/greenhouse/cold frame
You have little or no control of the water so check the parameters.
Do you get surface ice in winter?
The PH for example will affect your choice of plants.
Chop an IBC in half. two square meters of grow bed about 40 cm of media. Clay pebble or gravel depends how much you want to spend.
A 3000 ltr pump is about £30 and should do the job. Some sort of coarse filter on the inlet.
Flood and drain f/d or constant flood cf, are two sides of the same coin.
As are siphon or stand pipe. My choice would be fd and stand pipe. In which case you will need a timer
I would use 22m plastic pipe on the inlet side and 40m push fit for drainage.
Screwfix, other stores are available.
Good Luck
Titus

moat photos please

If I had a moat I would go with sharks w/ lasers personally... I'm just say'n

A moat sounds awsome - i hope you dont have to have a pool fence around it....

We're really going to need to see some pictures.

I'd just pump straight from the moat into the grow beds, and let it drain back into the moat. Doesn't need to be more complicated than that.

However, you might run into some problems. Get an API master test kit, and see if you have any nitrate readings, or if it's being diluted too much.

Other things like iron will be a problem, it's usually not added naturally, and adding it to the water will be a waste of time considering your water volume.

So to fix that, you might need to do semi regular foliage applications (spray onto the leaves) of iron & other trace minerals.

Depending on what you want, a DWC system might thrive in that situation, you won't need to worry about filtering, might need additional aeration depending on the natural DO.

I'd seriously love a moat around my house (with a drawbridge), would be awesome.

Oh creator above please let this be real. We need a member with a moat, we don't have that yet. If this member could have a draw bridge I second that would be awesomeness. Amen.

Hey Colum a customer of mine might be purchasing a drone for us to capture video footage for their website. Just the "toy" version that everyone is using but its almost as cool as your gopro, till we crash it anyway.

I am with Pond_Sucker, we need a member with a moat. I want a moat! Pictures please!


Would you like some basil and Jade Perch with that latte sir?

Build thread- viewtopic.php?f=18&t=21974&start=75

Based on the member's location its either;

A)Eltham Palace


B)Starborough Manor


or my favorite...
C) Castle Grayskull


No matter how you look at it I say its a win win...

Sorry for the slow response guys - I didn't tick the box to get email notifications on replies.


I'll try to answer all the questions people have replied with:

- Consider a poly tunnel/greenhouse/cold frame. - It needs to fit in nicely with the surroundings. I want something minimal to start with and we can expand from there.

- Does it freeze in the winter? - Yes, and sometimes hard enough to walk on. We won't be running it under snow and ice - what is the best thing to do in the winter to stop damage? Just cover it and empty the water?

- I'd just pump straight from the moat into the grow beds, and let it drain back into the moat. - That is what I've been thinking. I'm worried about blockages though in the grow beds from the sheer volume of solids in the water. Is this likely to become an issue? A DWC system might fix this but I was hoping to do gravel / clay pellet grow beds as I think it'll be easier to make it look nice.

- Iron levels, nitrate levels... - can someone point me to some guidance on what the levels should be for the plants? I will test the water. As you said we can't add anything to the water as the volume is too high so whatever we have is what we are stuck with. If I post the results of the water tests maybe you can recommend what types of plants would work best.

- Does anyone know if this will help filter and clean the water. It would be lovely if it was nice and clear some day.

- Eltham Palace... - really? Although the third photo looks familiar - I don't remember inviting you round Pond_Sucker . The house is near Angers in rural France so we get good summers but still very cold winters.


As promised a couple of photos below. I had these already, and will add some more in the next couple of days.
The first image is as you walk into the garden we plan on putting the AP system in, the second image is as you walk in a little further. I will get more photos from other angles so you can see better.

You can already see the edge of the bank with the reeds down below. I'm planning on either having our growbeds overhanging the moat held up on stilts above the reeds or having them up against the wall on the other side of the garden. If we did that we're going to need to bury the pipes going up and down from the moat - this is easy enough as long as they don't get blocked up too often - does that tend to happen much? Will having longer pipes be much of an issue?

Sorry my imagination goes wild sometimes. Your place is beautiful I'm thrilled to see that its nearly meats my Castle Grayskull expectations. I hope you find some method to add an AP system to that garden. Or maybe even a method to apply AP concepts by irrigating with your moat water?

Have you considered a green house?

Hi Hugh
I am reminded of that old song,” Me -and- my- chateau.” with apologies to ‘Old Blue eyes’
I digress!
Your place looks great.
My ten cents worth;
Use a dirty water sump pump on a flexible hose and position it in a deep part of the moat.
Pump to an RFF ( filter, many designs on the site) use the residue to fertilize the soil garden. Place this against the wall and drain by gravity to two grow beds. IBC chopped in half.
These are ugly.
However incorporate them into a deck, maybe semi -sunk and wood clad.
Let the water outlet fall into the moat.
Open a bottle and chill to the sound of water!
PS
Allegedly, you can catch cray fish on a piece of bacon on a string dangled into the water.The Kennet and Avon canal near my house has many crayfish and is very dirty.
You could purge overnight in clean water and then cook and eat.
You might say, “They taste delicious” I couldn't possibly comment.

Thanks Its my parent's place really but I'm in charge of the aquaponics project

I've thought of just irrigating with the moat water. Right now the garden irrigation is connected up to the well which is just abouts drinkable - nice if you want a drink in the garden but moat water would be better for the plants.

We have a green house but it's up a long way from the moat. This little garden is a lovely spot, near the kitchen and very low above the water level so it's ideal for our lettuce and herb garden. Most things grow well up in the veggie patch but the rabbits are all over it and always steal the lettuce.

The real aim for me is to clean the water in the moat so that the fish are edible. Most of our food is from the garden already but my mum can't grow her lettuce with the rabbits. Our first idea was just floating rafts of lettuce on the moat itself but I don't know if the roots would survive the carp and the moorhens and ducks would probably eat the lot.

I'm more an engineer than a gardener and automating the garden in some way is what brought me to aquaponics in the first place. The last plant I bought I forgot to water and only my cactus has survived, but I'm growing lettuce over my fish tank no problem

hughht5,

You could do floating rafts on the moat itself. You would just have to "cage" off a section below the rafts to keep the wildlife out. Possibly with netting. The dirty water rated sump pump would also work well. Plumbed underground, to keep it pleasing to the eyes. You would defiantly need a filter because of bits from the muck layer being pumped into your new system. From there, planter boxes, placed right on the ground wood clad would do the trick. But with the shear volume of water in the moat. Coupled with the already meter thick sludge layer on the bottom. It would take an awful long time to "clean" up the moat with a small AP system. You may not even see an appreciable dent in the moat, right away. But it would benefit over time. Both from the filtering, and the added aeration of the water falling back into the moat from the AP system. I know this is not going to be popular. But Given that your main priority is trying to clean the moat. Maybe you should approach this from a different angle. Firstly Pick up you "dirty" water rated sump pump. That your will eventually hook to your AP system. Use it as a fountain to help aerate the moat. While at the same time using a commercial pellet product to "clean up the muck".
Like this for example http://www.aquaticbiologists.com/bacter ... er-pellets
Then once the muck is under control. Build your AP system to keep it under control long term. Although I am hoping that you will ignore this and build a massive AP system and wait to eventually get the same results.

I think we'll find something other than an IBC - I'm sure there's something lying around. Whatever it is I think wood cladding would be sensible and help make it fit in nicely.

For the RFF system I think this could potentially solve our problem cleaning the water if we can scale it up. If we put a small pump into the moat with a coarse filter around it and pumped all the water into a RFF with the clean water draining back into the moat the sludge could be tapped out the bottom every few days and as you say used on the rest of the garden but especially removed from the moat.

I'm thinking the large RFF we build will be completely separate - we can put that out the way in the field so it doesn't have to look so pretty. Do you think it could work? With a certain size RFF what are the running costs (pump wattage) and how much volume of mud / solids do you think we could get out every week?

Thanks for all the help everyone

I like your approach to this

The idea to clean the moat is really my project for this. I want it to be a giant aquaponics system of sorts in that I want the fish and crayfish to be edible. The idea for starting a small but scalable AP system is because my mum wants a lettuce bed and it conveniently goes hand in hand with my project.

In terms of using pellets we've looked down that route before - total cost was several thousand $ and it'd probably just go back to it's original state anyway. I think something more passive is really the only way.

If we were to make rafts of lettuce we'd need to make them accessible and cover the bottom from the fish. I expect we'd need to keep the moorhens out from the top too. I'm tempted this summer to just make a small raft of lettuce and see how well it goes. If it's not destroyed then we could make a whole load. We'd need to design something to 'anchor' the rafts and to lift them out to somewhere we can reach the lettuce. I don't think getting a boat is the way forwards