Backyard Aquaponics
A place to discuss aquaponics

Hi Domani,

I will double check the charger to make sure it is good to use.. thanks for the tip!

Does anyone know if these filter pads have any kind of anti bacterial agent in them? I assumed not since they were for Eheim fish/pond filters... but wouldnt be good if they did

So i have a problem.. i didn't place my waste drain outlet for my Radial Flow Filter in the bottom of the barrel (because it would have been more difficult to place the barrel on something with pipe work coming out of the bottom) I thought that it wouldn't matter as I thought that if i placed the output for the waste drain lower that the inlet then it would siphon down to the lowest level of the inlet.. like when you siphon fuel out of a 20L fuel can to your car which is at a lower level.
However it is breaking the siphon effect before it reaches the bottom of the inlet!
Could someone suggest why and perhaps a solution? i thought that perhaps the size of the pipe is a problem and that 25mm is to big and that air is getting into the pipe breaking the flow? Perhaps I need to angle the horizontal pipe down?
Any suggestions would be helpful
See diagram for a better explanation...

Why do you need to empty the barrel>?
Don't you just need to take the sludge off the bottom?
I manually do this with a hose that I fill with water and then siphon out while moving around.

But in your case you might try increasing the diameter of the pipe inside the barrel - even a flange?

If the end of your waste line was longer and drained into a bucket so that it became submerged and couldn't suck in air, would that allow it to completely empty?

How high above the bottom is the waste intake positioned?

Its simple hydraulics... the water weight is equalising. As mentioned, the aim is to remove the better percentage of solids, which should be mineralised and then re-introduced.

it is about 1/2 an inch above the bottom of the barrel.

if it is sucking in air then that may help, I will give it a try. Although I have never needed to submerge the hose when siphoning fuel.. but still worth a try.

Well I like to remove all the water up to the outake level as when I drain it and stir it up there end up lots of bits floating in the water.. I have ball valves on the water intake so I turn that off when emptying it and on and off a little at the end to flush out the remaining bits.

Hey Tom,

In regards to your drain for your filter,

Make the outlet into a siphon.

- place a 25-40mm reducer onto the 25mm pipe inside the filter to act as a flange.

- cut the vertical drain out let pipe at a point lower that the bottom of the barrel.

- fit a straight connector to the bottom of that pipe.

- insert a restrictor inside the end of the 25mm pipe inside the straight connector, (mine is several sizes of hose stuffed into each other)

- fit your ball valve at any point under the straight connector,

- seal all the pipes to avoid air getting in around the joins.

This will act as a pressurized siphon, every time you turn the ball valve, it will start the siphon and with the 25-40mm reducer acting as a flange, i an certain you will achieve the effect your looking for,

I hope the picture makes sense

Best of luck.

Your system is a credit to you, is on of my favorites.

Regards

Hi Porter,

Thanks for going to all the trouble of making a diagram and detailed description, it is much appreciated!
and I'm glad your enjoying my system thread!
I will definitely add that flange and construct a reducer on the output end as well ( I imagine a reducer fitting like 25-15 mm would work in the same way to the inserting of hose into the end of the 25mm pipe..or perhaps just an end cap which I drill a small hole in?)
Currently my 25mm ball valve sits on the horizontal pipe.. do you think it matters since when I open it the water is sitting far above the height of the ball valve anyhow and therefore should continue to flow? I could cut it out and replace it but it seems a bit messy if not necessary... or it would probably be easier to leave it in place and buy another one and add it where you suggested.
Thanks again for advice

Hi Tom,

If the filter drains just by gravity as soon as you turn the ball valve on in its current position, then yep for sure leave it where it is, once the water hits the restrictor, it will begin the siphon effect. (as long as the restrictor is below the bottom of the filter barrel...even by an inch will work)

As for the restrictor, the most effective way i have found personally, (all my GB siphons are constructed like this) is to create a little 'bell' under the restrictor. The straight connector acts as that bell when it has pipe going in at the top and coming out of the bottom. The bottom pipe needn't be very long, say an inch or two tops?

I would strongly suggest (from my tinkering to get mine right) the restrictor be around 1cm long and open enough to still cause the restriction, but not to closed to get blocked all the time.

Regards to you,

Thanks Porter,

I just went to the hardware store and bought some PVC fittings and will try them out next time I am at my system which won't be for a week or so.. but I will let you know how it goes.
Thanks for the advice!

Big thanks to Porter (and Jayendra who earlier also suggested the larger flange in the filter) for the very descriptive fix for my RFF problem.. it now works great! Added the flange and reduced the size of the output pipe at the exit with reducers 25mm-20mm-15mm.. the barrel now drains within a mm or two from the bottom