Don't remember specifically, I had my water treatment company custom build one for me per my specs (gallons per minute, gallons available per day, expected water usage overall, etc.). The model/brand doesn't matter so much, as long as the process works. I went dual-tank because I didn't want to have periods where one tank was regenerating (this process takes 3-4 hours and CANNOT be done any faster than that due to the science involved) and I might be adding un-softened water to my pool -- I didn't want that. So the dual tank system helps because water will -always- be softened even if one tank is regenerating. A dual tank system (depending on your tank size) could be $1,500-$4,000. I went overboard on mine, so my dual tank system can effectively treat 23,000 gallons PER day if need be. (I wanted it so I could FILL my pool with the system too each spring). With a softener, the ion exchange process converts iron to sodium, so it doesn't filter it, it changes it at the molecular level. Also, you will end up with a Calcium Hardness of 0 coming out of the softener, and you/we have a plaster pool, so that means, making sure you add in the appropriate amount of Calcium Chloride to your pool (you won't do this at new plaster startup though!! again, check with your builder or Pebble-Tec when its' safe to start upping the CH level in your pool). Calcium Chloride such as:
Amazon.com
