The CHOP system is an acronym for “Constant Height One Pump”. This is the most efficient way to run an Aquaponics system.
The basic principal is to use the force of gravity to assist us where possible. This brings high efficiency in electric power consumption and plumbing design.
The CHOP system is also better for the health and wellbeing of the fish, as it means there is more water in circulation that brings stability in both temperature and pH. Because the fish tank is always full of water, the fish are safe if something goes wrong with plumbing or pump. The auto siphon system is an automatic way to flood and drain the media beds without the need to employ float switches or timers. The system is lower maintenance than older system designs that required float switches, timers and a second pump.
CHOP or Constant Height One Pump has been adopted by Aquaponics enthusiasts around the world and its popularity has demonstrated the methodology’s effectiveness. The other variant CHIFT PIST (Constant Height In Fish Tank. Pump In Sump Tank) runs in a similar way. In fact CHOP as an acronym was coined because the acronym CHIFT PIST was thought to be a little clumsy and crude.
Constant height in the fish tank is important in that we want to have a system design that ensure that the fish tank cannot be run or pumped dry should something go wrong, such as a pipe failure somewhere in the system. If something goes wrong and the sump is pumped dry and or the media beds run dry, it is not desirable but it is not a disaster as would be the case if the fish tank is pumped or drained dry.
One pump is important from an economical operation point of view. So, our plumbing design is such that all the water can be moved around to all parts, in the volumes we require for each section of the system, by the one pump.
The pump resides in the sump. All pumping is done from here. I like to call the sump “Grand Central Station”. It is the central meeting point of all the water flow in the system. The water is pumped from the sump to the fish tank, and from the fish tank the water runs by gravity to the media beds. The auto siphon or timer allows the bed to fill then drain back down to the sump. In this way there is only one regulated flow around the entire system and that flow rate is dictated by the auto siphon/s.
CHOP system methodology allows us to use the absolute minimum of power to move the water around. Aquaponics systems are perfectly natural systems except we have to move the water, and we can only do that with pumps of some sort or another. So, over a period of time we have strived to get our pump size down and enjoy a very minimum of power usage. In CHOP systems the water flow in one direction is done by gravity and in the other direction it is removed from the sumps back to the fish tank by the most efficient pump possible.
Originally, our systems had two pumps in them all the time, one was required to move the water out from the fish tank and one to move it back and we quickly discovered that that was just a waste of energy. This is another advantage of the CHOP system.
CHOP 2 System.
Chop #2 is a further and much improved variant to the standard CHOP methodology. We noticed a problem with water levels whilst working on a small commercial CHOP system we were commissioning. Running the feed water from the fish tank via a filter then on to be distributed to each media bed by gravity flow was problematic. If all the beds were not precisely level with each other the lower bed/s would receive more water than the others. This could be regulated with valves on each bed water inlet. This works fine on small systems, but the larger the system the larger the pipe work needs to be in order to accommodate sufficient water flow by gravity. Evenly distributing water by gravity to six beds that together were 30 meters (98’) long was near impossible.
We needed to refine the process for our client, so we came up with a solution that has been working well for several years, and now on many thousands of home systems and a good number of commercial systems. Pumping the water to the media beds, positive pressure delivery instead of gravity delivery. It is relatively easy to ensure even distribution to each bed and also to the most distant bed delivering the water by positive pumped, or header tank pressure. The system water is delivered to all points under pressure, either by pump or from a header tank. The pump is located in the common collection and distribution point; the sump. All the water arrives from the various parts of the Aquaponics system into the sump, all water leaves from the sump to the various parts of the Aquaponics system.
Water is delivered, as necessary, in various loops to the media beds, the raft beds, the fish tank and if included, to the mechanical filter. The water is collected from each loop or system segment back to the sump. The water is delivered to each loop or system segment from the sump under pressure either by pump or header tank. The water flow is regulated to each part of the overall system by the use of a simple valve or tap. Very accurate flows can therefore be achieved. CHOP 2 allows the operation of each element of our Aquaponics system at its ideal flow rate. This multi loop arrangement allows much more flexibility in plumbing design and precise flow control through the various elements of the overall Aquaponics system.