I do a base price and upcharge if the pool is much larger or if they have a high number of trees, a very dusty backyard. I assume that each pool will have an attached spa, most of them do where I work. $130 a month is the price with chemicals included with an average customer paying $150 a month. Tool me about a month to figure out where I was losing money and if I needed to adjust pricing, I charged less at first and I was not making enough. Most systems are on chlorine, with 50 pools a week ($7500 total being billed), I generally go through an average of 50lbs of shock and 50lbs of tablets a week ($200). Occasional bottle of yellow treat or algecide ($16) and about $50 in other balancing chemicals. So regular chemical treatment is not where I was losing money.
The problem came for me when I included algae blooms in the pricing. That would jack my price per week up another $200 if a few pools had a significant algae bloom.
So now I include chemicals, but if they have an algae bloom I will charge them for additional chemicals.
Also, if a pool doesnt have algae or anything, you should be able to crank out a pool every half hour. It saves alot of time, and as long as the pools are clean, people are happy, they dont usually care if youre there for half hour or an hour. I do 12 pools a day in 5 hours if everything is pristine, 6 hours on average, and 8 hours if there are a huge number of pools with algae that day. Get a routine down and keep with it, saving time lets you do more pools in a day and more money in your pocket at the end of the week. But don't skimp on anything... if you skip something one week it will catch up to you the next and really mess with your time. The best way to get your time down from what I've found is just keep a routine. I get there, clean out the baskets and check the equipment, skim the surface, vacuum, brush, backwash (if needed), then add the chemicals, and it's muscle memory now.