My pool is about 26K gallons, has a Solar system on the roof about 25' above the pump, and is vinyl liner. Two skimmers, four wall returns on the opposite side and 4 returns located in a shallow end and deep end stairs/swimouts. I do NOT have a booster pump for a pressure side cleaner. I have constantly battled algae. Two years ago, I swapped out a sand filter for DE Hayward 48. This spring I will be adding a Pentair IC40 Salt Generator to my system, it is already piped to accept the cell. While doing so, I am going to switch out an old Hayward Super Pump (2hp) with a new pump. Trying to decide between a 2 speed pump and VF pump.
My current thought is that VF pumps are really just 3 or 4 speed pumps and not true VFD pumps that operate off of pressure. The decision of which type of pump is tied to the main question- how to control everything economically. The two VF pumps that have been recommended to me are a speck 1.65 and a Pentair VF. If I install a Pentair ET4 controller, when the solar valve opens, can I get the pump to switch speeds or to ramp up rpm? Can I run the pump at low speed during "off hours", medium speed when the IC40 is in operation, vacuuming or trying to use a pseudo pressure style sweeper, and highest when I need to overcome the head pressure when using solar? I am not tied to the Pentair controller, but as it replaces the power center for the IC40 salt cell, thought it best, but is there a better recommendation out there? Finally, if two speed is the best option, any recommendations on Make and Model. Operating sound levels are important as the pump is fairly close and exposed. Thank you in advance.