Apart from the reduce number of pump to one, this system will make the fish more comfortable due to more water in the system and the level do not change much during operation.
Below a simple diagram on the basic of CHOPS, in Murray's site there is a better illustration on the system.
- To avoid confusion on CHOPS installation, please refer to Murray Hallam's DVD or his other instruction on how-to construct this system. The illustration I made here is for brief explanation on basic CHOPS concept.
- Please check CHOP 2 it is an improvement of this : Here
On the above diagram I do not include the fingerling tank on the return line, this is optional in my opinion and it do not change the way this system work.
This system, water in the fish tank is maintained at a constant height above delivery pipe outlet, water flowing out will be distributed to growbeds and subsequently controlled by siphons. Its doesn't matter what type of siphon used here, if its work for you then its good.
Growbed outlet water collected by a sump tank and returned to Fish tank by a pump, according to information from Murray Hallam's site the pump is running 24/7. However I don't see the reason why it cannot be shut off at night.
One aspect of this system I find beneficial is the pump located after growbed, this reduce pump maintenance significantly due to "filtered water" in the sump.
As mentioned earlier this is an ingenious system, but with any Aquaponics system there are pros and cons. I do not practice this due to one simple fact that my backyard is too small for such a setup, so I am not able to elaborate on this design.
I do wish this system can be shut off at night, partly because noise, energy saving, reduce pump maintenance and also it will give some species of plants a time to grow and stabilized during that period.
To switch off the pump at night, it may need a bigger sump tank to hold all the water above the fish tank outlet. How big is the sump tank will depend on the size of the fish tank.
A word of caution on any sump tank system in equatorial & tropical regions you must ensure mosquito cannot breed in the tank, by either covering it with nettings or have few larvae eating fish reside in the sump.
With this system, it give Aquaponics enthusiast more way to setup their system and see which is suitable for their location, budget and space.