I agree with the hardness needed for tile ,pebbletech, and gunite. however it is unnecessary with above ground pools as long as you use a borax buffer. I have maintained public pools and large university pools and never EVER have seen or heard of a 3800.00 impeller unless it is gold plated and has a brass pole with entertainment next to the pool included lol/ with labor. I would be happy to do said work for a markup like that. an all bronze 575 volt 6' PUMP 3 phase (largest I have seen or used ) with a gph of unnecessary

. impeller price retail is 580.00 + labor . 75.00 for labor. this pump could be used for amusement park log rides / water slides etc with over 100' of head with 10,000 gph. . so if you got charged that I am sorry and I hope it didn't hurt. BTW this pump retails for 12k$.