Backyard Aquaponics
A place to discuss aquaponics

As I understand it. Water plus solids enters the centre of the drum. It then falls through the tiny holes in the bottom of the drum. As the solids clog the holes the water level rises. This causes the drum to rotate. Etc Various valves then trigger high pressure water to flush the solids away in a separate direction.
In other words; a solid separator. Size of the solids determined by the holes in the drum. Secondly self cleaning.
Now bear with me. I don’t mind being laughed at.
The man who never made any mistakes never did anything.
I have made loads of mistakes.

Take a blue barrel, the rear of a push bike including the wheel an old car tyre and a submersible pump.
Use a hole saw to cut an opening in the side wall of the tyre. This is the waste water outlet.
Ideally the cycle wheel should just fit into the interior rim of the old car tyre.
Cover the cycle wheel in netting. Follow the spokes so that the netting lies at say, 45* to the horizontal.It will also lie higher in the centre than at the rim.
Assembly;
The cycle wheel frame is secured to the barrel so that the centre of the wheel lines up with the centre of the barrel. The car tyre is eased over the rim of the cycle wheel and sits on top of the barrel. The cycle wheel is free to spin inside the car tyre.
The water to be filtered is directed horizontally onto just below the centre of the cycle wheel. The wheel rotates slowly. Clean water falls through the net into the barrel for onward use. Centrifugal force will encourage the solids to move towards the outside of the rim. The submersible pump is in the barrel. On a timer determined by trial and error it adds it’s flow to the inlet. This causes the wheel to spin faster and the solids are moved off by the greater centrifugal force into the tyre to be collected elsewhere.
Yes! It would be much cleaner in plastic etc. I liked the idea of old car tyre and bicycle wheels.
Real backyard DIY

This video of one might help form the image of it in your head.

Neat idea Titus, I think this idea might work, even though it isn't the way normal drum filters work .

So you're saying place the bicycle wheel horizontal inside a tire and have this over the opening of a vertically oriented barrel. Push the water out on top of the screen over the bicycle wheel, so that it spins, and the solids are gradually push to the outside then into the tire where they drain to waste. A bit like dust being thrown off a turn table. The majority of the water exits through the screen, minus the solids, into the barrel below. Hopefully I got it.

You might have problems with the wheel becoming unbalanced because of uneven solids buildup but otherwise I like the idea. The extra solids might cause the wheel to slow down, you could paint a white dot on the wheel rim and have a tachometer count the revolutions to determine when to spray off the solids.

Don't know if it will work but it would be fun to give it a go

OK. I have had a few drinks and probably overthinking this. ( Golden rule never post after drinking)
BUT
If you placed another tank T2 above the main tank. This tank contained a syphon.
You could then dispense with the submersible pump and timer.
Water would flow from T2 through the filter into T1. The wheel (bicycle) would turn slowly.
When the syphon kicked in; Increased water flow. Wheel spins faster. Higher centrifugal force. Cleaning the filter and sending solids to the separate channel.
Zero energy input. Just gravity.

You still have the energy to get the water up to the tank. A small motor might be more effecient. I am not saying that it certainly is, but that it very well could be.

I'm not too worried about the price in running the motor to spin it.

It'll only run as required, be that twice a day, or for five minutes every hour, just depending on stocking rates. But it wouldn't cost much to run.

I do plan on making one for my next system (at next house with more land). I wanted to pull apart a front loading washing machine, open up the catchment outside the inner cage. But the pump/motor and things like that are already there. Then just hack apart the stainless cage inside, put the mesh in place. Inlet though the front door, outlet through the back, then it's just a matter of fiddling to make it work.

Then actuated valves to open and shut automatically to drop the the solids into the plant part of the system.

For some reason, I always had it in my mind that drum filters spun faster, when really the point of the drum is to make it self cleaning. Water just flows through a mostly stationary drum. Maybe a little bit of very slow rotation, just to expose new screen. But then I would be worried about the solids drying on the screen, causing it to be harder to clean. Probably the most complicated part of the build isthe seal between the drum and the stationary bit that seperates the "dirty" side from the "clean" side. As far as the self cleaning part, that looks quite simple, just a spray bar with a trough on the inside to carry the solids away. A float switch (or if youare a geek like me, perhaps a field effect sensor) on the dirty side would trigger the cleaning process.

There's some DIY drum filters on the Koi forums. Don't have the links handy sorry.

I posted some in Chris's thread a little while ago.
I've found the Koi people are good at them:
http://www.koiphen.com/forums/showthrea ... e-made-RDF
http://www.koiphen.com/forums/showthrea ... 23-Diy-rdf

This one looks the easiest:
http://koi2day.com/forum/index.php?topic=6157.0

This one I'd try for, with things added like electric valves that auto dump into the MT tanks.
http://www.koiforum.co.uk/water-treatme ... 010-a.html

Hmm, 3 out of four of those links don't work for me. Anyone else have that problem?

Sorry, I cut an pasted from Chris's thread.

Second time lucky:
I've found the Koi people are good at them:
http://www.koiphen.com/forums/showthrea ... e-made-RDF
http://www.koiphen.com/forums/showthrea ... 23-Diy-rdf

This one looks the easiest:
http://koi2day.com/forum/index.php?topic=6157.0

This one I'd try for, with things added like electric valves that auto dump into the MT tanks.
http://www.koiforum.co.uk/water-treatme ... 2010-a.htm

Thanks, still couldn't get that last one though

me either??

Here's a pretty simple design. I like simple. http://www.aquatechmfg.com/Rotary%20drum%20filter.html

I have been doing a little more research on my horizontal filter idea.
The bicycle wheel is now replaced by an electric car radiator fan.
The filter mesh would be stainless steel ,75 microns
On balance a 25cm diameter fan and a sheet 30cm /30cm of SSmesh work out the most cost effective at around £22
This would nominally give me a filter area of £R2 or 3.14 * 12.5*12.5 = 490 cm2
The fan motor is water resistant. The 12v motor could possibly be used to go to cleaning mode (higher C Force) but I really want to try it first just with increased water pressure.
At this thickness the supplier says you can cut the mesh with scissors. The fan blades end in a plastic rim. The idea is to bend the mesh over this and secure with SS wire. Like sewing. ABS plastic and SS can you glue?
The weight of the mesh will be (cut) around 25 grms.
Any tips on working with SS mesh?
For trials I am thinking two buckets one inside each other.
Fine sand is around 250 microns so I will probably use that as trial debris
Any advice more than welcome