Backyard Aquaponics
A place to discuss aquaponics

You may have seen my first system which was the revamp of my old backyard fishpond, if not you can check it out in this forum. It was a good little system and I had a lot of fun building it, but I ran in to a few issues with it. The main issue was due to the lack of a standpipe in the growbeds to keep the hydro clay out of the drainage tubes, the system would clog occasionally and the hydroclay and seedlings would float upwards and almost overflow. Once the clay floated up the clog would usually dislodge itself, but the rising and lowering "tide" was swamping the seedlings. It was also a little ugly and in the way, so I spent the past few days dismantling it and salvaging parts for my new system.



As you can see the new system is comprised of black poly tubs, 4 x 220L tanks (2 not shown so you can see the detail of the stand) and 4 x 160L growbeds.

Now before you guys start about the poly tubs... The plan is to produce fancy Goldfish and "blue" Yabbys for aquarium use (not for consumption) and I am going to try my hand at some Australian natives and potted colour in the growbeds (ie - all ornamentals). I'm still not convinced about the dangers with using poly tubs, I've read the "Questionable Materials" thread backwards and a heap of web pages, what is the difference between this and black pond liners, or pvc piping, or black rubber tubing? Its hard to find out exactly... (though someone will no doubt tell me) Steve made a good point IMO in another thread that when you compare aqua produce and commercial produce and things like the levels of pesticides that the commercial products are subject to, surely the end product in such an aqua system would be "safer". Anyways...




The stands were constructed using 6 x reconstituted limestone blocks and some spare timber that I had from my pergola. I employed the 'Fat Bastard' engineering principle when designing the stand, and managed to salvage roughy 1200L of water using my poor man's rainwater system which helped with both the load bearing tests and washing pea gravel. More to come on that saga later...




The four tanks were joined using some fittings that I found at the evil 'B' warehouse (it's impossible to walk out of there without spending ca$h), the outer pairs were joined in a low position and then the two pairs were joined in the middle with the same fittings in a high position. The logic being at least if I spring a leak only 50% of the tanks will empty to the lowest level. We'll see how sound that logic is come the event of a disaster .

I then rigged up autosiphons in each of the growbeds and setup 90mm PVC standpipes in each to keep the gravel out.




Then I prepared myself for the grueling task ahead.... (drumroll).... Washing Rocks!

hi simmo i found washing rocks easy dump them in the back of the ute and hit it with a fire hose

whoa! I need a bigger screen.
But it looks good.
especially the syphons.

Yeah sorry, will try to resize them down a bit. Its fine for me, I'm running at 1680 x 1060 (Widescreen).


(poser)

There you go...

I purchased a trailer load of pea gravel, and used my trusty old wheelbarrow to transport it all to the back of the house. From there I washed the pea gravel, one colander worth at a time, and put it into the growbeds. This took a RIDICULOUSLY long time. I'm not joking... I can really empathise with you guys now and can only wonder at how EB managed to do all his growbeds. Its sort of like an initiation ritual.

So, for all the effort and pain involved (my hands look like that of a 60 year old and I have a strain in my side from repeated heavy lifting) I thought it justified at least a few pics of rocks and the washing progress. Unfortunately, I don't have any kids or a wife to rope in to help me & the GF was away on business, so it was just yours truly putting in the hard yards. So we have some gravel in the pic below...



And here they are from another perspective...



Fascinating stuff isn't it...?



Did I mention I hand washed the pea gravel manually, one colander full at a time. Well you wouldn't know it from the pic below. Every time I moved the gravel around this was the result.



I went through the 1200L of rain-water I salvaged in half a day of washing, and it took me 2.5 days in total to get the system draining with reasonably clear water.

One tip I can pass on though, the only thing I managed to get to stick to poly tubs was "Blu Tack" which is usually used for hanging posters etc. Silicones and a few different types of marine + aquarium sealants and plumbing tapes I have tried have all failed to bind to the black poly plastic and the other plastic tubs I used in my previous system. Blu Tack did the trick and the advantage is that as it cools it hardens, the cold water makes it "set" and it is almost 100% waterproof. You can see it sealing the siphons below.

Nice one Simmo, I'll be interested to see how it all works....

Oh and just to make you feel bad, I had a call from a couple who came to see me two weeks ago and bought the manual. In the last two weeks they have built a replica of my big flood and drain, gravel cleaning and all... So what I hear you say.....?

They are great grandparents.....

OK, the grandkids evidently helped with some of the gravel cleaning.....

Yeah, when i started cleaning my gravel to start with i hated it. But as i got into a rythm it was almost relaxing. (but still time consuming)

Interesting use of blue tack by the way

aaah!....and that's all ahead of me
must admit I don't feel so bad using concrete blocks to prop up my grow bed(s) now

Is it blue tac or knead it?

Knead it heh.

Seeing as I am heading away tomorrow, I'll post the next few pics of my progress... I finally finished washing all the gravel so it was time to get the system full of water and cycling. I filled the tanks half with rainwater (we got some more rain in Perth during construction) and half tap water, adjusted up the ph to ~7.5 and set about the process of cycling the water through the system.

I still needed to filter a little of the dirty water coming out of the growbeds, so I turned the last bed's siphon around and ran it through a couple of tubs (that were the yabby tubs in my old system), that way as the red clay settled at the bottom of the tubs I was able to bucket the clean stuff back into the system. The overflow from these tubs went onto the lawn via the garden hose shown.



I cycled the system for a couple of days, then introduced some yabbies and goldfish (just 8 of each) in the middle 2 tanks. Yabbies left (Pinchy is centre of the shot), Goldies right.




The system works in a simple flood and drain setup, as you can see above the pump is situated in the leftmost tank and pumps water to each growbed simultaneously. Each growbed floods to the top level of the siphon bend and then empties to the tank situated below it, as the leftmost tank empties quickly due to the pump being placed in it, there is a reasonable flow of water through the tank connectors from right to left that balances out the water level across the 4 tanks.

simmo, you've got it bad

nice work

Too true Steve... but my first system was becoming a bit of a burden. First it only clogged once every 2 or 3 days, but the more solids that got deposited in the growbed the more the clogging problem worsened, to the point where I had to leave the whole system off for a couple of days cause I didn't have time to fix it but couldn't let it run because it was clogging roughly 1 in 4 flood/drain cycles.

I wanted to get a system up and running that was stable and low maintenance, and with the addition of the standpipes this design is far and away more reliable. The siphons have initiated and stopped automatically without fail and with no "leaking" problems and I am confident I can leave this system now for a week without any human intervention besides a little food for the fish and yabbies.

Yeh, i hear ya...................I seem to be doing too much talking and not enough doing..........pulled out my silver beet today as the roots were all rotten. bok choy seems to be doing well though, but need to get more than just a "maintenance bed" going. Your and simmo's pictures are good, beasue tey make me feel bad, and thats when i get moving Just as EB LOL

I'm still holding onto the winter and jade perch temperature excuse.................