Robl45, they put one in when it was installed and it would over chlorinate and error out. They told me it was the smallest one available and took it out. I also hadn't considered backwashing salt water on my hillside full of old growth oak trees.
Actually my chlorine demand is 4 ounces per day, just looked it up. I did some research and found I can get a normal size pump and run it for a short time once a day. If I get a 10gpd pump it will need to run 4.5minutes per day. If I get a 3gpd pump it will need to run 15 minutes. If I did my math right... I looked up the Stenner Pump 45mhp10 and found it for $300. I just need to find a timer that controlls to the minutes. Or build one. Any ideas?