My variable speed pump should be listed in my sig and I'm trying to determine the setting. I'm not sure what my TDH is but it would have to be pretty low I think. The pump is about at water level and is about 40 ft of run to the pool and the pool and spa is about 17 ft X 33 ft. I think the plumbing is 2 inch to the pool returns and intake and 3 inch to the spa jets. I lowered the RPM to about 600-1000 is about the same and it increases at 1100 RPM so based on the graphs in the user manual I'm guessing my TDH is around 9-10 ft (Not sure if it works that way).
I was running at 3450 RPM about 6-7 hours a day which I know now is way overkill at around 144 GPM if I'm reading the graph correctly. I'm thinking I can drop to 1500 RPM and run 6-7 hours a day and be fine.
Second problem - Even running at that rate it doesn't seem to be putting in enough chlorine. I am only at 0-1 PPM FC and TC when putting in 2-3 tabs per week and having the chlorinator completely open. The flowmeter at the front of the chlorinator dropped significantly and I'm not sure why. Before I had added tabs it would max out when completely open. Now it only goes about half way up the window at 3450 RPM and maybe a 1/4 of that at 1750 RPM.