Bio-organic Planting | Building the Siphon | [ Part- 2 ]

This is the second part of the Bio-organic Planting series. If you want to read the first part please click here.

So we move on to building the siphon.The big question would be "Why do we need a siphon in the first place?" The plant roots can decay if it is completely submerged in water for prolonged periods. There is also a need to aerate the roots for healthy plant growth. A constant cycle of flooding and emptying the plant growth medium is the best way to go. If we keep a simple drain at the bottom of the planting container the flooding wont happen and  if the drain is kept at the top, it would cause continuous flooding. So both these options are not feasible. The solution is therefore to use a siphon.

The siphon that is best suited for this purpose is the 'bell siphon'. It does three things :- starts the flushing of water from the growth medium at the required flooding level, maintains the flow even as water level drops and can also cut the flow at the specific required level to  maintain a minimum safe level of water.

 The bell siphon consists of three main parts. The inner pipe, the larger outer pipe sealed at the top and a water level sensing tube. Here is how it works:

• Water fills the tank and reaches the level of the inner pipe and starts flowing down the pipe.
• This starts a flow and creates a suction that continues because of the larger outer pipe maintaining a vacuum inside.
• As the water level reaches the lower tip of the level sensor tube, it sucks in air and breaks the vacuum thus stopping the flow and the next cycle begins.

 Below are a few snaps of a simple bell siphon I made out of left over pieces of pipe. I have sealed off the top part of the outer tube with a piece of acrylic which was cut in a circle. Ideally you can use an end cap to seal off the end.
Click the button below to view the steps involved:

The pump that I used in the project was a low output fish tank pump, to fill the growth medium container. So I used an inner tube smaller than the pumps inlet tube. If this is not done the siphon wont work properly for low output pumps. If you have a high discharge/output pump the recommended inner tube diameter is twice that of the inlet diameter. Test the system with the siphon in place before adding the growth medium and fine-tune it if required.

In the next part we will take a look at the growth medium and setting up the pump.




Index:


Bio-organic Planting [ Part-1 ]

Bio-organic Planting | Building the Siphon | [ Part- 2 ]

Bio-organic Planting | Grow-bed & Pump | [ Part- 3 ]