Backyard Aquaponics
A place to discuss aquaponics

Here is my design for an adjustable automatic float ebb and flow valve for both small and high level differences.

I have had 6 of these functioning impeccably for 4 weeks now in long shallow hydroponic gutters between my top (fish) tank and my growbed.

The hollow ball and the (modified) Styrofoam float are standard parts I bought in a specialized sanitary hardware store.
Brand names: SIP for the ball and Torrent for the Styrofoam float (I haven't been able to locate the manufacturers).
But you can easily make them yourself.

The adjusting ring is a simple stainless steel washer which I have bent a little.

greetings

Frank

more pics

frank

That's a great design, I have to try that! Some questions, though?

1. How did you manage to get a watertight seal between the 'ball' and the axis?
2. It doesn't drain completely - how much water is left at the bottom when the valve closes? An inch or so?
3. Do you think this would work for big growbeds as well (not just small gutters like yours)?

Your device takes up less space than a flout, but I think it can work with lower inputs than an autosyphon!

Is the ball that you used a toilet tank ball?

the "balls" I bought actually are threaded, but if you would use any self adapted ball two nuts on the axis fixing the ball in place would surely do the job even if the seal is not perfectly tight.
There is a big hole in the bottom of the ball through which any passing water droplets can trickle down into the drain and are replaced by air which keeps ensuring the ball's buoyancy.
When the ball pops up, the upper hole and two securing nuts will be above water level anyway. No more water will penetrate into the ball at this moment which is when it counts.


that depends on the weight of the assembly which will decide when the valve closes again. The lighter the assembly, the lower the level. This is why I hollowed out the float. Hollowing it out even more will impede it from adding to the weight.
I have not measured, but on eyesight it is maybe 2 cm in my setup.
adding an extra buoyancy ring attached to the ball will make this remaining level even less. Then it will only close at the last moment.
Slowing down the drain output will diminish water speed and the suction that traps the ball back in closed position. Just don't slow it down beneath the input capacity (see further below).


the valve isn't aware of the size, length, width, or depth of the growbed, (and I don't plan to warn it), so yes, it will work with any growbed size (I have tested it).
Just be aware that increasing the level difference will increase the water column thus increase the force necessary to open the valve thus calls for a bigger float to achieve this (tested that also).
Same goes for a bigger ball and a wider drain. In this case it is the increased surface which will call for more dislodging power.


it will always work with any input, slow or fast (tested this also). Even a trickle will make it work.

Only when the input exceeds the drain capacity the ball will keep floating and fail to close.
That is the limit of any system.

greetings

frank

yes it is, they come in different sizes here in Belgium (brand name Sip, size used in this setup 61/45)
I had to hold them for a second or so against a grinder to eliminate the barbs (poor finishing!) because they didn't close perfectly at first.
I used standard washbasin drains, available anywhere.

greetings

frank

putting the whole drain system on a slightly lower level (or in a cavity) will ensure draining to almost the last drop.

greetings

frank

thanks for that description
googling on your description led me to the following links:
http://plumbing.hardwarestore.com/51-29 ... balls.aspx
http://www.plumbingsupply.com/flappers.html (bottom of page)
http://www.cornerhardware.com/eljer_toi ... 6958/40139
http://www.hardwareandtools.com/invt/6208896
http://www.azpartsmaster.com/Products/T ... _9101.aspx

and more...

they come cheap enough not to bother making your own balls

frank

Brilliant Frank

Now I have a use for those toilet cisterns in the back of the garage.

in fact a toilet cistern or any other small tank mounted next to your growbed(s) as a connecting vat could serve to mount the DIY automatic float ebb and flow valve in. If the bottom of this tank is a bit below the bottom of your growbed(s) they will drain to the last drop. This would take all the hardware outside the growbed(s) which is another advantage for maintenance.

drawings made with Google Sketchup

Frank

like this:

I know
But I could never get the buggers to autoflush, only dribble.

What is the size of these things? It is difficult to tell from the pictures. Also, how do you manually post smilies (I forgot the format)?