Backyard Aquaponics
A place to discuss aquaponics

Sick of maintaining a backyard pool but also reluctant to dig it out as there is no way to get machinery in there I've finally committed to turning it into a pond with the eventual plan to add grow beds etc at a later stage.

Rectangular concrete 9m x 4.5m 60,000L in ground pool, 30+ years old. Quartzite coating. Main drain blocked up a few years ago due to it cracking due to a small earthquake. Salt chlorinated.

Over the last week I drained and cleaned the pool and fixed a few loose tiles and the underwater light housing which was originally installed incorrectly and therefore leaks through the hose containing the electrical cables. I need to run a sealed hose back to the electrical outlet and join it to the existing 1m long concreted-in hose instead of replacing the existing one. This I can do in the next few weeks.

I backwashed the sand filter with fresh water and cleaned the pipes, set the sand filter to recirculate after dumping all the water and disconnected the salt chlorination unit. For now I'm leaving the pipework as it is but will likely remove the sand filter and the old pump that was once used for solar heating. I will use the existing Pantera PPP 750 (750watt) pump on a timer and add a venturi to the line somewhere, but would like to invest in a more efficient pump at some point. I also have a air pump I will connect in the next week just as soon as I make a diffuser.

To do in the next week or so:

Install venturi
Make pipework to bypass the skimmer box
Make diffuser for air pump
Wait for chlorine to burn off
Add some plants
Pull up the pavers around the pool

Overall plan:

Establish the pool as a natural pond
Plant it out with duckwweed, water chestnuts, bullrushes, lotus, etc. I want a good amount of coverage to slow evaporation.
Consider 'free' ways to run the pond (windmill, solar, hamster in a wheel)
Introduce native/local fish
Introduce local yabbies and mussels
Setup a couple of floating nets to contain Silver Perch and Trout
Slowly expand to include growbeds

I've read the following threads for ideas and knowledge and have a whole lot more ahead of me (thank you, but am more than willing to hear advice or suggestions. Wish me luck.

Slowboat's pool to pond conversion:
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=16397&hilit=pool
dandm's barra pool/swimming pool:
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=4396

My pond as a pool:

Nice pool to start your setup with .

Lots of potential there

Another thread to look at is PLJs

viewtopic.php?f=18&t=12883&hilit=plj

Is that the sump tank

Funny you should say that, I actually dreamed I installed a larger pool in the split level above this one and covered the neighbors yard in grow beds! I must be thinking about AP too much.

Thanks Terra, I've added it to my list of threads to read.

Update - 2 weeks in

All the chlorine has evaporated and my Freshwater Master Test Kit arrived in the post, my water is now a nice emerald green but still transparent. I've potted up the following plants using coconut choir in the bottom of the pots to prevent the mostly clay soil escaping with stones on top to keep the soil in. I haven't fully submerged any of the pots yet until the roots develop enough to hold the soil in place.

* Running Marsh-flower (Villarsia reniformis)

* Whorled pennywort (Hydrocotyle verticillata)

* Nardoo (Marsilea Drummondii)

* Knotted Club-rush (Ficinia nodosa)

* Pale Rush (Juncus Pallidus)

I'm hoping to find some Sacred Lotus (Nelumbo nucifera) locally and will also grow duck weed (lemna minor) and watercress (Nasturtium officinale) of which I have seed. I have a lot of planting to do yet!




As with anything to do with this pool I've had an impossible time trying to find anything that will fit into the supposedly 40mm pressure pipe outlets that return the filtered water back to the pool. My plan was to install a couple of venturis on these but the outlets seem to be a non-standard size (43.8mm internal diameter) so have put this on hold until I can make something up to fit. The bypass for the skimmer box is a similar story and will need a custom fitting made.

The valve in the working air pump I stored in the shed a few years ago seems to have fallen to pieces in the heat. I intend to repair this but forked out on a larger air pump (Pond One O2 Plus 12000 60 watt 3yr warranty) that will do 11Lpm that will allow me to recirculate the pond water and give me enough lift to install a biofilter down the track. This also means I shouldn't need to run the 750 watt pool pump at all (at least for now) meaning the air pump will pay for itself within the year.

Does anyone have a calculator for airlift pump design? I intend to install it in the deep end which is around 2m deep and can feed 11Lpm of air into it if need be. I'll pull the water from 50cm off the bottom to prevent picking up all the naturally collected organic matter (leaves, sticks, etc) that I'll have SA yabbys feeding on.

I've also found it very difficult to find a source of native fish in SA (short of pulling them from a creek) but will keep looking. I hope to try for some (not native) Redfin Perch at a local waterhole one night this week and may throw some of those in the pond for the time being (presuming I catch any) since you aren't allowed to return them to the water once caught.



Currently browsing PLJ's thread for more ideas: http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=12883&hilit=plj

That is going to be an awesome aquaponics system. I've done a bit of work with air-lift pumps. http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=23206&start=2400Ultimately, this upgrade to a bigger better airlift pump was a failure. It may have been a fail because my health and mental state were terrible at that time. A Google of air-lift pumps should provide you with a lot of information. I do know it doesn't take a lot of air to move water if the air diffuser is properly built. I run ours from the air pump used to oxygenate the AP.
Brian

some good airlift theory and examples on youtube.
If you are practically minded you can pretty quickly work out an option from seeing working examples.

I recall quite few pool related ones when looking at air lift a while back,
though quite often it is trial and error.
If you want the maths there are full calculation theory - eg. see bottom.

(a) simply a large diameter pipe will not give much lift but it will give a big flow rate.

a lot of high volume airlift is used to make a small lift waterfall into a converted pool.
(eg. 1-2 foot to half meter or so 0.3 to 0.6m)

(b) Airlift is dependent on the ratio of depth water in pipe to height of lift, so a deep pool is good.
> hence there are quite few airlift videos on youtube shown in pools,
> and in groundwater world and undersea applications the ratio is massive

(c) pump sizing is both not too big and not too small. the ratio of water to air bubbles is important for optimal efficient lift.


this is technical but covers a range of designs...including tapered tubes and air-injection methods..
https://www.researchgate.net/publicatio ... ng_systems

Good overview > https://www.koinet.net/j/index.php/arti ... art-1.html

terrible voiceover but good information > https://www.youtube.com/watch?v=03EmME_OB-s
(nb. it starts with an oil explanation without pump, but that is used to show the density effect - as he says at 4min50s - in airlift this is achieved with air supplementation)

If you need fitting and any C1 filter material PM me have about 200 litres of C1 and a good price. Plenty of Pvc fittings water and air pumps as well cheers bear

Thanks ccBear but what is a C1 filter? Google tells me its a photography thing, are my photos not up to your standard?

C1 is similar to the K1 filter material, set up a drum with a large airstone so it is just rolling the filter material over and this encourages the bacteria to grow and eat the nitrate.

[attachment=0]62DBFABB-7A68-4B3A-AD50-8047772860D4.jpeg

Update - 3 weeks in

No pictures as not much as changed as yet, I am waiting on some fittings so I can complete my airlift pump to circulate the water more economically than my 750 watt pool pump. I've thrown in a couple of handfuls of Azolla and Duckweed, added a potted Bacopa Monnieri, and 10 small local Murray Rainbow fish (Melanotaenia fluviatilis). I have various other sedges potted up getting watered each day to settle the dust before adding to the pond, and have thrown in some packets of Splosht (beneficial bacteria starter) that were given to me to hopefully get things progressing quicker (I'm a little impatient). The dragonflies have moved in already and I had the local blue fairy wrens drinking from the pond this morning too.

Considering biofilters and all other things simultaneously and I considered whether a biofilter made with shell grit media would not only work as a biofilter but also buffer my PH? I read that shell grit in a system will stop being dissolved once PH reaches 7, is this right? My only concern was whether shell grit as a biofilter media would be oxygenated enough for the bacteria to thrive? It would certainly provide enough surface area. Thoughts?

Damn, wish I saw this sooner..

A few thing's.. It Aerate the water.. A Air Lift system to suck the Bottom of the pool to the surface works Well.. You could most Probably add a Catch basket to the out flow of the Airlift to catch any large matter from the bottom of the pond that is caught up in the airlift..

I would Highly suggest that you work on a Better More Power Efficient Pump to Circulate the water thru a Better than sand Filter system..

Sand Filter are good if you want to run a Pool..

Just thought of Some thing..

Check out Natural Pool's.. it Might Mean that you need to Drain the Pool again.. But with your system you could possible add a divide that would contain natural Bio filter..

Juergen

Hi Ashram, I have some experience with Bio-ponds AKA Natural (swimming Pool) ponds you might want to consider.
Back in 2008 we were constructing a dam in the lowest area of our property to act as a water feature and irrigation for our garden.
We stumbled across an add in a magazine about Natural swimming pools by English designer Nigel Littlewood hence we bought his book and began to redesign the partially dug out dam to suit the requirements of a self cleaning pond.

Our pond collects leaves, dust, bird droppings, insects and rain water from the the house & shed roof and occasionally lawn run off. Over time all these additions break down and create nutrients that would turn the water green and full of algy if not consumed.
Heavier debris like sand, dirt and water logged branches reside in the sludge at the base of the pond and assist with the decomposition of other heavy arrivals. Also at the lowest point is the pick up T tube for the 12000 lt/h circulating pump which lifts the coolest nutrient rich water up 2.0 m into the two 600 deep x 1000 x 9000 mm grow beds. These beds on each side are half full of river rocks about the size of apples.
The cool water displaces the warm water which flows over into a slightly lower GB before flowing over into the main body of the pond.
Plants thrive in the GB's and need to be trimmed back annually and the pond needs to be drained every 3 years to remove sludge. This process is in fact the removal of inputs over the last few years.

Our pond has a liner and is more difficult to clean than a flat surface although draining and leaving for a couple of days to let the sludge solidify a bit helps.