In S Florida the pool service rates are pretty cheap. The rates that SoFlo has mentioned seem about right. There are a lot of pools and a lot of pool companies. I get stuff stuck to my door or in my mailbox for a pool company at least once a month. In my neighborhood probably 90% of the houses have pools, with close to 95% of them with pool services. In fact I am probably the only one that takes care of his own pool.
You could keep your gas cost down by restricting yourself to just a few neighborhoods. If I got 100% market share I could probably get 30 pools in my neighborhood alone. Word of mouth goes a long way as most people dont like the services that they are currently using. Make friends with real estate agents, they will be a great source of leads.
As for
@SoFlo Tech questions:
2.5 gallons of chlorine 10.5% about $7.50 from Leslies you might be able to negotiate a commercial price from them
2 gallons of MA is $16 from Home Depot
40# of Salt about $5.50 from Home Depot
I would only work on SWG pools since without tabs you wont be able to keep them sanitary. Tabs are just too expensive now also.
I would also consider buying a few S200 and just dumping them in the pools and come back 1.5 hrs later to remove them. Easier than vacuuming/brushing and will leave a cleaner pool for your customers. I also think you are underestimating 10 min for a brush and vacuum.
Also a lot of companies charge extra for CYA additions, so you may want to consider that.
I would also invest in some sort of web site that you can show what you have done, plus post their test results. Picture of the clean pool, picture of the clean filter (I would only clean the filter once a month). Be a little better than your competitors with useful communication. Just think how cool it was when Amazon started leaving pictures of the delivered packages. Or maybe just email that information to your customers after every visit. A lot of your customers will be snowbirds and that extra level of care when they are out of town will go a long way.
The big money is also made in the post clean up after a hurricane. That is not included in most of the service contracts and can be up to about $400.