CHIFT PIST is short for “constant height in fish tank, pump in sump tank”. This is a very good idea for an easy to maintain aquaponics system but there are always drawbacks to any aquaponics system. Someone has to still clean out the extra waste in the sump tank and since this tank is typically below the fish tank level, you still need a pump to move the water back up to the fish tank. The advantage is there are fewer pumps and plumbing needed for this type of system so in a sense, the CHIFT PIST is probably a good system to start out with for a beginner in aquaponics. As I build out my system, this is probably the way I will go so I get my “feet wet” so to speak!
Typically, the pump in the sump tank will be on some sort of timer, which when turned on, the pump moves the water from the sump into the fish tank where the overflow pipe will flood the grow beds with water from the fish tank. This allows the water level in the fish tank to remain a constant level. I’m still a little confused though on how this system will move the fish solids (aka fish poop and such) to be moved to the sump since I’ve always seen that the poop in my aquarium sank to the bottom of the tank. Maybe there is a siphon or some type of agitation done on the bottom of the fish tank to stir up the solids so they overflow to the grow beds and hence to the sump. I’ll figure it out I’m sure.
Some advantages of CHIFT PIST through my reading and research:
- The fish tank only has an overflow pipe at the top of the tank.
- No pump in the fish tank is needed. Although you may want to add additional aeration to the fish tank to keep those fishies happy.
- Additional water in the sump giving the system more stability.
- The water level is always right at the top so the fish are happy.
- The pump is in the sump where the water is clean and filtered free of fish solids.
- The sump tank acts as a buffer against extremes in water condition which may give you some breathing room while the system balances itself out.
- The sump also acts as an insulator to the fish tank water temperature. If your grow beds are in direct sunlight, the water that is flooding the grow beds can get fairly warm which is something you don’t want to pump back into the fish tank directly. The water has a chance to cool down before it is pumped back into the fish tank. Typically, the sump tank is buried which helps to keep the water a consistent temperature.
I am currently designing my system and sourcing the materials and such but will be posting more on the system as I get closer to starting the actual build-out. Feel free to comment about your system or if you want more information about aquaponics. I will respond as quickly as I can with some answers or at least point you in the direction where you can find the answers.