How an Aquaponics System Works: Animation


Here at Ecofilms we’re big fans of Aquaponics. We think its so good that we run a system outside our office that was designed and built by Murray Hallam an Aquaponics pioneer here in Australia. But how does it actually all work? Many people have problems trying to get their heads around the plumbing and technical aspects of fish and vegetable grow beds. They say its too complicated and too technical to build a system themselves. So we asked Murray to explain in detail how it works. We created this flash animation that was used in Murray’s DVDs and are sharing this knowledge here and explain some of the secrets behind the auto-siphon and why flood and drain is the way to go for the backyard hobbyist.  The home DIY hobbyist could build these systems if  they understand two things. How the  AutoSiphon works and the general layout of an Aquaponics System.

The Auto Siphon or Bell Siphon

If the pump is the heart of an aquaponics system, then the auto-siphon are it’s lungs. A vital part of kit. Remember when you were a little kid and the teacher told you about the regular flooding of the Nile river and how fertile the Nile delta was to early farmers. Well think of the auto siphon as a kind of similar concept. It’s main purpose is to flood the grow bed drawing rich oxygen into the depths of the trough, oxygenating the plant roots and turbo charging the bacteria to do their thing.

Click on the Red Button below in the Flash animation to start the system. Click the button again to end the animation.


The flood and drain cycle is powered by a small pump either located in a sump or in the fish tank itself. The pump can run by a timer or be  permanently on. The drain cycle varies depending how large your trough is and how fast the water is pumping back into your grow bed. The one we have here at home flood and drains on average every 14 minutes. A smaller grow bed will drain faster. It doesn’t matter how long it takes as long as the plant roots are well oxygenated. The bacteria are living organisms that process the fish waste through mineralization of  the solids into nutrients that the plant roots can readily absorb. Thats why aquaponics works so well. It mimics a living eco system. No chemicals are used. No pesticides are used. Your cost is only your plant seedling, some fish and your power bill to run the pump. Our system costs us $100 a year to run and works brilliantly. In fact it just gets better with age.

So how do you build a auto-siphon? Are there any moving parts? No none at all. The trick of the siphon is to create an imbalance in air pressure that forces the water to drain rapidly. There is a fine little plastic tube that is an important ingredient to the siphon. Its role is to break the suction immediately so the grow trough can fill again with water. Many problems with auto siphons can be traced back to the break air tube not activating properly causing water to endlessly dribble back to the fish tank. Having too much or too little water pumping into the grow bed can also create problems of flows. When the siphon is in balance, the system will run for months without adjustment.

The CHOP System
The animation below is a CHOP system. It stands for Constant Height One Pump. The term was coined by Murray Hallam although other aquaponicists may know it as CHIFT-PIST which sounds like something you do in a public urinal! That term also means Constant Height in Fish Tank. Pump in Sump Tank. So much for the terminology. What does it all mean?

In early aquaponics systems the pump was located in the main fish tank. This would work quite well. However a constant draw of water from the main fish tank to the grow beds resulted in the water level in the fish tank rising and falling to the ebb and flow of the siphons. If there was ever a problem with the pipes such a connection hose leaking then the pump could drain all the water out of the fish tank resulting in dead fish.

In the CHOP system however the pump is located in a separate sump. If the pump malfunctions or any pipe fittings break, there will always be water in the fish tank keeping your fish alive. The water from the main fish tank falls to the grow beds below by gravity. Water must find its own level. It can’t flow uphill. But it can flow downhill. So the water level in the fish tank will always stay perfectly level. Only the water returning back to the tank from the sump will cause a fresh load of water to fall by gravity back to the grow bed and sump. So the system repeats in an endless cycle. Notice the pipe drawing water from the bottom of the main fish tank? Any fish solids are drawn from the base of the tank and deposited into the main grow beds as fertilizer for compost worms that help the system thrive. The whole system is powered by just one small electric pump. A 4500 litre per hour pond pump. Additional grow beds can be added to make the system even more elegant and productive.

More details about Aquaponics is discussed in the Aquaponics Secrets DVD that goes into a lot more depth and detail than can be mentioned on this page.