A more detail posting of this Siphon : Here
Its Video : Here
The more I fiddle with the mini Siphon the more I like it. First mini Siphon I did using 15mm (1/2 inches) PVC pipe and fittings, this size is finicky and prone to failing.
I then resort to increase it size to 20mm (3/4 inches) as used on my single barrel kit sometime last year and had it running without problem since. This smaller size siphon was not really fully tested, since it just work and I assumed that it function as its bigger brother that I normally use.
Being small has its advantage, cheaper, easier to make and together with less water inflow requirements makes it ideal for small or solar powered system.
Before it can be deployed successfully, I need to make sure that it is able to tolerate varying water inflow. Otherwise it can't be use and would be a problem in maintaining it to work properly.
I have tried various water inflow, so far the result is encouraging. More test need to be done and I'm aiming to retrofit one of my bigger growbed to use this siphon.
Below diagram of mini siphon if anyone interested in making one.
With smaller size reducer used, if you can't get a reducer then its possible to hot flare the 20 mm (3/4") PVC to make a funnel on the stand pipe.
Additional note : 11th May 2011
The dimension between top of stand pipe to bell should not be less than 1/2" about 12mm. If less than this over time as the siphon get algae build up it may fail. Making it not less than this length will ensure trouble free operation.
If you find that its difficult to stop a siphon this may be the problem, try increase it. Insufficient distance can cause difficult to start, and if started difficult to stop.
On the 25 mm stand pipe siphon (its bigger brother), if reducer used is 32/25 mm then the 50 mm bell can be use for it too, making the 25 mm and 20 mm Siphon share the same outer dimensions.
Photo above showing the 25/20 reducer on the stand pipe with 50 mm outer bell. The reducer is placed on top, this was a quickie job, ideally I will make its as short as possible then use 25 mm pipe as extender to adjust water level.
I will try making a flared funnel from that 20 mm pipe, its its work then its even better. Most complaint I received is due to the non availability of the reducer in some parts of the world. Making a flare funnel is an alternative for those that having this problem.
Above with 32/20 reducer in place.
25/20 mm reducer used, with 32/20 mm reducer as comparison. Test conducted so far so good. Later this afternoon I will get more pebbles for my growbed and get it done properly.
Above a "High Water" siphon outlet that I am also testing, its not a requirement that you use this type. High Water outlet in action below, more job need to be done. Water overflowing the aeration breather.
The double elbow job as below do fine for most installation but I need the high water outlet due to my water level problem. Its only 6" clearance between my growbed and the highest water level point.
I know the mini siphon works after few days of trial, however the longer time needed to fully test it to see what plant roots will do to it if operate at prolong period. So I will monitor it for 3 months.
Pebbles loaded growbed done, now for more serious test.