That's a good idea, to get Ben's input. I gather Louisa's pool will be a commercial enterprise used to swim dogs. That presents an entirely different filtration issue from a pool used by children. She won't have to deal with urine (dogs don't pee while actively exercising) but she will have a lot of dog hair. No sun tan lotions but dander, instead. In my mind, for her 9,000+ gallon pool she'll want a pump and filter that does the job reliably well, not just something that'll get her by.

Louisa, be ready to do a lot of refilling and adjusting the chemical levels. The dogs will drag out an inordinate amount of water each time they exit the pool.