Looking for some verification on the correct pump size for my pool. In ground 15,000 gallon, 1.5in pipe, 2 returns, 1 skimmer, no water features, no spa. Currently use an automatic pool cleaner (baracuda) connected to the skimmer and have solar heat panel on 1st floor roof about 8ft up. My current pump is a 3/4hp Jacuzzi High Head and I would like to replace it for a few reasons. Based on the reading/research I believe I would be ok with a 3/4HP Hayworth Super Pump or a Super II Pump (or Pentair Superflo). However when I reached out to a couple of pump resellers, one suggested a 1.5HP Whisperflo while the other one suggested a 1HP Super Pump and advised against the Super II. I am not sure but it seems that a 1.5hp Whisperflo is a bit much and even a 1HP Superpump the same. If I am not mistaken at 40gpm a 3/4HP would turn the water over in ~6 hours. Am I off here and I am better off with a 1HP ? Superpump ? Super II ? I am leaning towards Hayward simply because there are several local distributors but honestly not set on it. Appreciate any guidance.
I am also replacing the existing 50cu ft cartridge filter with a 120-150 cu ft filter. A secondary question is the 150cu ft filter has 2" ports and my pipe is 1.5", any issues with reducing this to 1.5" ?