Do yourself a favor,I was quoted at 350 for a 3/4 or 1hp Goulds pump i forget which. Im a Service Tech. Every one of our well guys uses goulds. I put a well in last year too. im only 13ft down,live right near the ocean,and have a literal river running about 10 ft down. I was so excited to get water with the pitcher pump after never doing anything with pumps in my life.i ran out and i bought a utilitech pump at lowes. It works great.I know you probably wont pay 350 but not to to much more. Goulds are the best pumps out there IMO,and all our pro pump guys too. Im not a pump guy,i know how to prime them and troubleshoot. if you have any questions about your irrigation though. POST HERE and ill help u out with anything i can. i love talking irrigation lol. if you get a no name like i did.nobody can really help you with them.Goulds are tested and participate in shows,research.and have actual stats pros can interprit. Just figure out your Gallon Per MIN,and what the pump puts out and youll be good to go.you can always just increase or decrease nozzle sizes so it doesnt cycle. good job though doing all that though if your not in the field.

I had a single speed Jacuzzi that lasted for 20 years. It started getting noisy which I took as getting near the end. I upgraded to a 2 speed pump for savings on the electric bill. I run it on low 95% of the time. High speed only for chemical dispersion. Like you I did a rehab going to salt, new filter, new liner and cover. 15 years is pretty good but the noise could be a bearing starting to wear. I am very pleased with the 2 speed option.

I just went through the same thing. Gunite and plaster pool, about 24000 gallons. Upgraded my old single speed 1-1/2hp Pentair Whisperflo pump with a Pentair VS pump. Replaced my Pentair Clean and Clear 240 cartridge filter with a Pentair Quad DE 100. The filter could easily be considered oversize for my pool, but the Quad DE will filter better than the old C&C, and the larger size will give me longer runs between cleanings. I like the "hybrid" aspect of the Quad DE. The ease of cartridges, the filtering of DE. I'm going to direct-plumb the filter, meaning no multi-port valve. I don't know much about Hayward, but I highly recommend the move to the variable speed pump. If they offer a 2-speed pump that might save you money on pump coast and running costs.

Assuming a basic system... The 3 way Jandy valve in front of the pump diverts water from the spa suction (floor or wall) and the pool suction (skimmer). If there is another 3 way valve very close to this one, it is for a dedicated cleaner line. If so, you'll find that port in the pool wall about mid pool and it SHOULD have a spring loaded flap on it. You can't open that flap if there is suction to the line. There will be another 3 way valve above the first one. It diverts filtered water to the pool or spa. Depending on the system, if the valve is 100% to the pool, there should be a smaller line that tees off below the valve and serves as a bypass to the spa return for a spa overflow during filtration. So, you have a pump that puts water into your filter and then goes to the heater and finally back to the pool. That pump has a basket that needs cleaned out on a regular basis. If the filter is indeed clean, check the pressure. When it rises 7-10 psi, it's time to clean the filter. In there, you will find 4 cartridges that need hosing. The more time you spend on them , the better. Fire the heater a couple of time per month to keep it in good working order. The display on the heater should be a digital display. It will give you options to toggle between pool or spa. Both settings heat identical, it is pool/spa specific for convenience. One for your favorite pool setting, one for spa. If you install a suction cleaner, you can't go wrong with "The Pool Cleaner". Yes, that's the name. About $425 but worth every cent and it will not fail you compared to most other suction cleaners. Beyond that, you should find a qualified tech in your area to go over the system. With many foreclosures, and we have a billion of them here in So. Cal, we find lots of issues with these pools that have sat for months without care. Yours looks good because the bank paid a few hundred bucks to clean it out but believe me, that's about all they did. You'll want a complete water analysis, an inspection of all the rubber in the valves, pumps and filter. Guaranteed they will leak if the pool sat for more than a month or two. If they are not leaking now, they will. The heater may also have become a home for rats in the owners absence.