Making an Auto Siphon for an Aquaponics System

What You'll Need
Hose/tubing (Flexible)
PVC fitting or adapter
PVC pipe lengths of two different widths
Flexible rubber hose for air tube

In an Aquaponics system, auto siphons are used to control both the flooding and draining of the growbeds, which are the beds where plants are grown. Follow the easy procedure listed below to make a Looped Auto Siphon System and a Bell Auto Siphon System.

Making a Looped Auto Siphon System

Looped Auto Siphon is also called the U-bend or Gooseneck Auto Siphon and is an easy siphon to construct. You can buy siphon tube lengths from any hardware store to install it yourself.

Step 1- Constructing a Loop

Construct a loop using the flexible tubing and place it in such a way that the crest of the loop is below the surface of the growbed.

Step 2-Mounting the Loop

You can choose to mount the Looped Auto Siphon either externally to the growbed or internally, but make sure that the outlet is below. 

When the water level in the growbed reaches a height that is above the lower level of the horizontal part of the Looped Auto Siphon, water begins to drain. The siphon begins to work effectively when all the air is removed and the water level rises to the top of the hose. The siphon becomes fully engaged when the air is expelled from it and the growbed drains the water into it. Air is then introduced into the hose again when the water level of the intake has dropped. When buying materials for constructing this siphon make sure that the hose is flexible enough but has thick walls. Also make sure that the loop you make is round and smooth and the outlets of the hose end in a vertical drop.

Making a Bell Auto Siphon System

Step 1-Creating a Standpipe

Cut the PVC pipe to its appropriate length (depending upon on the size of your growbed) and create a standpipe which you will place vertically inside the growbed, so that it extends through the base of the bed.

Step 2-Setting it Up

Cut a length for another free-standing siphon pipe that is larger and place it over the standpipe. Fit the top end of this pipe with an end cap.

Step 3-Incorporating the Air Tube

Cut the length of the air tube to the desired level. Make a hole on the upper edge of the siphon where the end cap is fitted and then fit the air tube. The purpose of this air tube is to break the siphon when the water level drops.

A siphon is created when water flows upwards between the walls of both the pipes and then inside the stand pipe. At the intake end of the air tube, when there is lowering of the water level, the siphon breaks. When you buy the pipes, make sure you buy the right size. The inner pipe should have a minimum clearance level for enough water to flow into the stand pipe. The outer pipe should also be large enough to allow water to flow between the walls of the siphon and the stand pipe.

Auto siphon systems follow the basic laws of physics and aren’t difficult to maintain. Nevertheless, constant care and cleaning can help you maintain your auto siphon system, enabling it to last a long time and work efficiently.