Backyard Aquaponics
A place to discuss aquaponics

After spending a bit of time throwing a few questions around I think I'm getting closer to buying all the necessary parts to put together my aquaponics system.

I have a 500L rainwater tank that I want to put to use, and am trying to get the top part of an IBC to use as the growbed.

I would greatly appreciate any initial feedback on this design. It's pretty basic and my engineering/drawing skills are extremely limited.

Hi Baz,

Nice easy design. Adjustments I would make is to allow the drain from the GB 'drop' into the FT, this gives you free aeration. Also Im not sure if you could get the syphon to break with the drain submerged under water. Also, if you have the option I would make the GB deeper.

I am basing this design on the design that Buson posted. Thought it looked pretty cool.

http://www.backyardaquaponics.com/forum/viewtopic.php?f=12&t=12991&p=337776#p337776



I have seen a lot of differing ideas as to GB depth in this forum. What GB depth would you recommend?

Ive never figured out how Bunson achieved this, I tried it and couldn't get it to work and came to the conclusion is was a mix of drop distance and pumping volume. Hopefully he will chime in.

100mm will work but personally I wouldn't go less than 300mm (its a documented good depth). More is even better as your maximising your filtration capacity. I think mine were around 400mm.

The "success" of the air-intaking-below-water-drain is relatively dependent on the inflow of water into the drain. Using a "wider" mouth compared to the diameter of the drain helps the intake of air which is mixed and released into the FT; it's very robust and it works well in a cylindrical tank. If you're going to add air via an air pump, better "swirling-push" can be achieved using a "sparger and jet" design.


There is a math model you can use to optimise the depth if the GB, but you need to know a few parameters: in general, the deeper you can make the GB, the more filtration you will have, which means the more fish you can keep BUT if you've got too much GB and not enough water in the FT you'll need a sump or need to use a continuously flooded model... If you think about the problem very carefully BEFORE cutting anything, the answer will become apparent. Note: the answer also relies on the different types of IBC frames which exist and how much support/bracing is available for the system.

[edit]See some similar computations here : http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=12452&p=331304#p331304

Just a couple of things, which have both basically been touched on:

a). As Charlie has already suggested, if possible I would make the GB a bit deeper, at least 330mm so you can have at least 300mm of gravel. If you are planning on having a few fruiting plants in it, especially tomatoes, I would suggest running the 400mm gravel depth, not for extra root space, but for extra bio-filtration, therefore allowing extra fish to be stocked and more nutrients provided.

b). Regardless of whatever method you initially choose to run the system as, for a 300mm gravel depth I would make the standpipe/downpipe either 20mm or 25mm, or if you go the 400mm depth I would definitely go 25mm standpipe diameter, because if you ever run it as a siphoned F&D system the 40mm standpipe will require a lot of water flow to get it working. Also, if you do ever run it as a siphoned system, for simplicity and reliability the downpipe/return line should finish above the water FT level and have a 90 degree elbow with at least 6" of horizontal pipe after it for back pressure.

You could get a IBC delivered off gumtree? I got the two units for $90 each plus $30 delivery,

I cut my IBCs at the 800ltr mark, wich gives you a 800ltr tank, and when you turn the top upside-down, you get a 300ltr plus container for your grow bed, I have 250ltrs of grow media in each grow bed,

With the IBC, before you decided what size pipe you are going to use? Find out what type off cap is on the IBC? The two I got had different tops, so I had to silicone both up and start from scratch, if you get the steal base IBC, like I did you will need to cut a hole for the cap in the base as I did, but because you will need to keep an eye on the bell, you may want to cut another hole as I did closer to the edge so you can reach it easily,

If you use the 20mm stand pipe 50mm bell and 100mm media guard as I have it should work fine,

I have a 19mm bulkhead from my grow beds, (they were the only ones I could find at first) I later found all sizes at Bunning’s in the bathroom plumbing section, I love Bunning’s!

If you want or need, to submerge you piping? I used a loose fitting around my bulkhead of 25mm pipe, with one 90deg bend on each pipe, I used the IBC frame to support the runoff pipe, placed the 90deg bend in place then just cut a 25mm piece of pipe to fit neatly between the bulkhead and the bend, this allows air to break your siphon and start it up easier,

You will still need to keep an eye on your water flow, as to fast of a flow into your GB will hang up your drain siphon,

I hope this helps you a little, good luck with your system,

Re the above, keep in mind IBCs come in 1000L and 1200L. blizzard must have the 1200L. You might have to make some compromises if you have a smaller IBC.
But, if you already have a rainwater tank to use for the fish, and you have the room - cut your IBC near enough to halves if it's 1000L one, and you can have two nice size beds, or it at least gives you the option to use the other half for future expansions.


Sent from my iPhone using Tapatalk

Do you think this 50/40mm invert from Bunnings will help with that?

http://www.bunnings.com.au/holman-50-x-40mm-pvc-dwv-taper-level-invert_p4757217



Thanks again Bunson. After looking at the calculations, I think I'll aim for 350mm.

.

With a CF or F&D cycle is this necessary? I'm hoping to have the drain directly above the FT.

I didn't actually know this. Most of the tanks I've seen on gumtree or eBay are advertised as being 1000L.

Are there many 1200L tanks around?

No, my tanks are one thousand litre tanks, but above the thousand litre mark you have the top section with the two sides and cap you get an extra one hundred litre plus, I put five 50ltr bags in each grow bed as they were on special around the corner 10 bags and over $33 each, there is still close to 80mm above the media even with the 100mm media guard,
Another hint! Shop for specials! As some things are cheaper if you buy ten or more,

And katmac, I couldn’t afford to fill half an IBC with expanded clay, and it would be hard getting a bell to work at that depth? Gravel would be cheaper but the weight would be over half a tonne,

But it would be cheaper than the clay?

Hey Charlie thanks once again. I was checking out some of the pics of your setup and wondering about the supports for your growbeds.

I am trying to figure out what to put the GB on. I understand it is going to weigh a fair bit and whatever is under it, needs to be able to take it.

I originally thought about building a table/support out of wood. After reading a bit, I have noticed some advantages and disadvantages with this idea.

I saw in your pics you have a steel frame. I was curious where I could pick up some steel like that, and exactly what I should look for.

Any other ideas about GB supports would be appreciated.

Baz

What is the "floor" where the system is to be located? Grass? Concrete? Tiles? Pavers? Wood? etc

It is going to be on dirt/clay in my front yard. Might take some picks tomorrow to give an idea.