Based on the excellent information shared by members of this forum, I have joined the “satisfied customer” list by installing a liquid chlorine injection system, using the 15-gallon drum and the Stenner pump that several others have used. My setup is shown in the following photos:
As you can see, the setup is quite similar to others’ here on the forum. The Stenner pump is mounted close to and above the 15-gallon chlorine storage tank. A short line is connected from the pump tube cavity back into the chlorine storage tank as a precaution against pump tube failure. Chlorine is injected in the return line downstream from the filter and the heater.
The Stenner pump is wired in series with the main pump so that it can’t run unless the main circulation pump is running. A separate timer controls the Stenner pump so that its duty cycle can be shorter than that of the main pump. The timer is a digital Intermatic, which can be programmed for as many as 8 cycles with duty cycles as short as 1 minute. This arrangement provides a high degree of flexibility in terms of operating the Stenner pump.
At first, I used a wood yardstick as a simple “dipstick” to determine my chlorine usage and the liquid level in the tank. This was a little messy, so I installed a simple “sight glass” made with a length of 5/16” clear flexible tubing. It runs from the inside bottom of the tank, up through a close-fitting hole in the top of the tank, down to the outside bottom of the tank and back up to the top. The end of the tube is vented to atmosphere. After installation, it requires establishing a siphon in order that the outside tube reads the same level as the liquid level inside the tank. Initially, I used a simple yardstick to measure chlorine usage, but I recently added the refinement of making a custom scale that reads in “cups” and “gallons”.
Overall, the setup is working well and I couldn’t be happier. With this system and using the BBB pool maintenance philosophy, I’ve had the most successful, trouble-free pool season in many years.
If I were to do it over, about the only thing I would change would be to use a fixed-output pump instead of the variable output. Currently, I’m running the pump at max output (the 10 gpd setting) and controlling the daily chlorine addition by adjusting the “on-off” programming of the digital timer.
Many thanks to those who have gone this route and shared their experiences. It has saved a whole lot of trial and error.