Backyard Aquaponics
A place to discuss aquaponics

That would have been really cool though.

Pfftt!

When I was a kid I did a backyard concrete block incinerator full of sawdust and diesel with a vacuum cleaner as a blower. Blowing the air into the bottom.

It worked pretty well.

That was a grade 7 thing our teacher did with us.

You wont need the drums if your not firing a clay body with the added materials for bloating. If you just add organac matter that will burn out leaving holes, and fire to no more than 1100c, you wont have any trouble with the sticking. The sticking is only really because the oxides required for the late stage gassing that causes the bloating will tend to melt when they turn back to their metals.

In a red clay the red is caused by iron oxide (rust) but in the firing, depending on oxygen, some of that will turn back to iron and can run if it's hot enough. But normally it wont if it's distributed throughout the clay body. Hydroton looks like they add extra iron and perhaps something else (mrs Bullwinkle says it looks like just iron) but there are a few other things that might do it.

The water thing Rup mentioned is genius.

If you get bone dry clay, and then either run water over it, or submerge it for a bit, particles start to dissolve and this would add hugely to the surface area.

I once filled a freshly made coffee cup (almost porcelain high fire stoneware body to 200 mesh) with water and a bone dry one also filled with water next to it. The dry one fell apart within a half an hour, and the wet one held water overnight. The water thing will definitely work best on bone dry clay.

But forget the lightweight bloating for the first batch.

Dig a pit
make a fire
roll up balls with different percentages of different organic materials
then when they are dry, chcuk them in. Make sure you number them so you know what you have done. There is nothing worse than having something that worked, but not knowing how you did it

I'd start with 10 balls with between 5% and 50% sawdust if you fire a natural clay too high, there's a fair chance the impurities in it will bloat anyway, so just see what you get when you fire the balls.

I'd also try a few balls without any sawdust, and I'd try the water thing. Just for a test, get a dry ball, hold it up and squirt it with a hose and you will see the surface change within a few seconds.

so make 20 balls numbered and recorded, make a hot fire the size of a carton of beer with the balls inside.

Pull them out the next morning and there will be at least one that will excite. I promise

Also its a really cool thing to make stone from mud with fire. If you make bread, and drink homebrew, around the same fire, you pretty much have all the main early human tech covered

If you dont mind a few crackles and pops, and you make the balls small, you will probably get away without drying them, or stick them in the oven for a 2 hours at 130c

anything by this digital fire guy says should be taken as fact, although he will no doubt talk about how to stop bloating rather than create it.

My kiln and all the kit is still at the old house on the farm, so I cant do any experiments with this stuff at the moment, but I guess I could dig a little pit in the garden.

do the test, post up some photo's (or email them to me) and I'll be able to give you some insight as to what's going on.

Each time you make some, it's easy to drop in some tests and improve until you have exactly what you want.

This stuff was being done by cave men, so dont be shy about jumping in. It's really low tech, and everything will work every time no matter what you do. clay + fire = rock every time.

wear eye protection if they are going in wet.

This is all so EXCITING!!!

We now plan to copy this idea and are about to go out and buy an airpump! Then we can do our own experimenting.

Some questions:
1. Do you have any concerns about even dispersal of nutrients into the GBs? Will you just let the water flow in from the 2" pipe directly onto the media in the GB? I was wondering if:
a) it would be better to let the water flow under the media? And
b) with only 1 entry point for the water, is it possible that all the nutrient-rich water would stay at one end of the GB and that plants down the far end would not get enough nutrients? Is a grid irrigation type setup an advantage or a problem?

2. What size will your return pipes be? Will you keep them as large as possible (50mm, 2") or will you make them the same size as the SLO pipe diameter (32.., 1 1/4")?




3. Bullwinkle, I understand the theory, but in practice, what would this involve? A 90 degree elbow? would you continue the pipe upwards into the IBC towards the top half of the FT, or would an elbow be enough, stopping a couple of inches within the wall of the FT?


4. I am going to have to read up on the air lift bell, I do not understand them at all! And I don't know why an airlift bell with holes drilled in the SLO pipe would work better than what Jimbo is already doing...feel free to explain if you feel inclined, but I'll keep reading...

5. Juergen, you recommended using standpipes in the GB to improve the return of flow. What would be the advantage of standpipes over Jimbo's drains in the bottom of the GBs (with the usual drilled surround for holding back media)?

6. Will there be enough DO in the system, or is a separate aerator required?

Does anyone think different media would have any effect on drag? Can this still be done with gravel?

Funny thing...we live on solar, and the inverter doesn't kick in until there is at least 7 watts of power being used...well, it does come on, but the power flicks on and off unless we are drawing more than 7 watts, so this system could use too LITTLE POWER Didn't think that would ever be a problem for us with aquaponics, ha ha!!



SO EXCITING!! Jimbo, thanks for doing so much experimentation. I'm wondering about trying two 1" pipes for SLO, as per velacreations suggestions...

Hey Blythe.
So far, I have very little experience with grow beds in the real world. To start, I'm planning on letting the water pour into one corner of each GB and have the drain in the furthest corner.
I am planning to try a 1" airlift sometime soon and also I want to try a slight change on the top end of the airlift if I can find the right plumbing parts.
For the return pipes, I'll have a 3" pipe going back into the FT and piping up close to the surface to get a little turbulence at the top of the water and in the opposite corner from the airlift. The drains from the GBs will probably have to be 1 1/2" looking at what's available, but that's 2 drains to one airlift. Should not impede flow.
The airlift bell as I read it was a chamber around the slo that you pump air into and the holes in the slo allow the bubbles in making it an airlift. This kept the airstones from restricting flow in the pipe. The way I put the adapter on the bottom kept the airstones out the way before I eliminated them. What is, I think, a fortunate side effect of this shape is that the reducer acts like the top end of one of Affnan's siphons and it might be acting like a venturi employing the bernoulli effect and accelerating the flow up the pipe. This is all wild speculation and may not be happening at all, but I still like the end result regardless of the physics and any complex mathematics that would be over my head anyway.

@Blythe, I'd say it probably wouldnt matter all that much if it was with a powerhead, but I think with an air lift you get better movement of water if it's in a pipe. As far as I can tell the air is lowering the density of the water within the bubbly zone and that water on average floats. Things float if they displace more by weight of the thing they are floating in than they weigh. So I think creating a discrete "packet"of bubbly water would make for a more floaty thing. So in a tube, I think you get greater lift, and thus flow. The longer and deeper the tube, the greater the air in the column at any one time, because the air is under water for longer, so that lump of water floats upwards for longer. So if it was an air powered exit tube, I'd say rise it all the way to just under the surface, but a powerhead wouldn't make much difference.

OR not, because the truth is I have no idea

I dont even have a working air pump

I bought one I cant use, then cut the cord off.

So in short, to answer your question

At least it would be easy to change, because with everything under water, theres no need to make anything watertight, so you could always extend the tube and see what happens.

I've built a test bed with some media and a fish tank, so tomorrow I'll stickytape something together to test with a powerhead, and If I get the electronics sorted with the air pump, I'll have a 2 watt (or slightly lower depending on some stuff I dont yet understand to do with square waves or something)

My new goal is to run a single blue barrel, half and half, side by side with zero head on the guts of a set of 5 of those solar garden lights that only work for a few weeks and the 10 nicad batteries they come with

And if that doesnt work, I'll plug it into the 3600LPH pump I have, and turn the FT over every few seconds, so at the very least, its a safe bet I'll be expanding in some way or another

@Blythe, I think media drag could be an issue with some media, but if you can fill the media screen around a bell siphon with water as fast as the siphon can pull it out, I think that will be free flowing enough. A siphon pulls a lot of water out quite quickly, and if the media allows the water to flow quickly enough to drain freely, I cant see why it would be an issue.

But I've not seen lots of stuff before.

@ Bullwinkle- hmm...I wasn't planning on incorporating siphons at all! I just assumed that if the GB and FT levels are level, when water is displaced from the FT into the GB, the water will automatically leave the GB in an attempt to reach equilibrium again...

Went shopping today to try to start this project. I think pipe sizes are a bit different here in Oz. Only high pressure pipe come in 1", and it doesn't come in y-connectors, only t's. Hope you have better luck, Jimbo,

I also think you did really well to get an air pump 9L/min for 5 watts. Most of the ones we saw average roughly 1L/min/watt. I've ordered a Resun online that does the 9L/min for 5 watts. They also had the 20L/min for 10 watts, but I figured if this works, better to get two 5 watt air pumps, eggs in different baskets.

Blythe... pressure pipe and fittings.... are common in 25mm, 32mm, 40mm, 50mm... and even larger sizes...

And you should be able to get even "y" pieces in good plumbing stores... Tadelink, Reece etc...

Or you can order online.... http://www.wetearth.com.au/YPiecePVCWYE

Good plumbing store...but I'm in Tasmania!!

How strange...the man who served us at a major plumbing store in Hobart is a plumber and told us they don't come in y fittings in 25mm, but maybe he was only thinking high pressure piping. DEFINITELY not in Bunnings down here. Might have to look online...thanks for the link!

Ooooooo...just checked it out....Y PIECE......

I wasn't actually suggesting a siphon, just looking at how freely the water moves in a system with a siphon regarding the drag of the media.

Whoever invented PVC would love this forum. People getting all excited over plumbing

2 more variables down the drain...or out the side and in the bucket as it may be.
1" schedule 20 pipe (sch20 thinner walls, same outer diameter-more volume) was slower than 1 1/4" pipe.
Also, I tried a sweep elbow at the top of the airlift and then the tee in a horizontal configuration wondering if pushing the water around a smooth bend and then letting the air out would increase flow any, but I actually lost a little. I don't know if this disproves my theory or if it was an imperfect test since 1 1/4" sweep 90's aren't available here and I had to bushing up to 1 1/2" for the sweep. Maybe I'm losing velocity there? Oh well.
I think the peak of efficiency with this pump may have been reached with the 1 1/4"/32mm pipe.
Started cutting a pair of drums today to fashion up some kind of kiln. I want to have something repeatably useable instead of constantly digging in the ground. And I like building things to learn from.
I think I'm done flow testing, so I can put the buckets to work slaking clay!

BTW, BW. This is where I was reading about firing earthenware and misapplied 1000F. He actually says 1400F for the firing of earthenware.
http://www.goshen.edu/art/DeptPgs/rework.html