I looked for older threads on this first, but didn't find these answers.
I just went and spoke with three different local pool stores and got stupid answers - even my high school son who was with me couldn't believe the inability for any of them to answer questions.
Like everyone else, I need to go from a 2hp single speed to something more efficient. But, I want to do it smartly.
First, I first found a decent answer on this site that the reason a VS is better than a 2 speed is because you can set the GPM and it changes speed to maintain that speed. So you know that you are doing a full turnover in a given time. But for a 2 speed, that's all you have and your low speed only works if you have calculated the right hp to get the GPM so you can set the right duration. Although I also read on this site that for a residential pool, you don't need a full turn over.
Here are my questions based on those statements:
(1) If I were to take the time to do the calculations and get the right HP 2 speed for my pool, why isn't that as efficient as having a VS that gets to that rate anyway?
(2) Is it true that there is no magic requirement of one turnover a day?
Second, the two reasons I'm not wild about the VS are because I hear they still don't last very long and their price is so high. It seems to me that if I could get a $400 2 speed that is right for my pool, I'm way ahead of a $1,000 VS - even if I install it myself and lose the warranty. Then on this site I saw that someone referenced just buying a separate 2 speed motor and put it on my pump: 56Y Square Flange In-Ground Pool Pump Replacement Motors. At $200, I'd be even more ahead of the game (as long as I can map out the right hp). I had asked one of the shops I went to about this. The salesperson said that the pumps are different and more efficient on the VS.
(1) Is that true that the pumps are changed for VS?
Finally, I have a 23,000 gallon pool. The visible pipes into the pump are 2". But, I have no idea what is under the ground. The only think I know is that in the skimmer, there is a diverter valve that adjusts if the water into the pump is coming from the drain at the bottom or the skimmer. And the hole that goes from the diverter valve to the pump is 1.5". Does that mean I really just have a single 1.5" pipe?
Thanks for any advice!