Monthly comparison
DIY pool chemicals add up before you do any work.
This uses small consumer-size Walmart purchases, because most homeowners do not buy chemicals in bulk. The math converts each package into a per-gallon, per-pound, or per-ounce cost, then applies estimated monthly usage so leftover product is not counted as wasted.
Walmart 2-pack is $11.94, or $5.97/gal. Summer usage is about 2.5 gal/week, or 10 gal/month.
Walmart itemSmall 5 lb bucket is $39.97, or about $7.99/lb. Two 6 oz tabs/week is about 3 lb/month.
Walmart itemOne 4 lb bag for the monthly hardness adjustment in this estimate.
Walmart itemSmall 5 lb bag is $9.57, or about $1.91/lb. Estimate uses 9 lb/month, the middle of the 6-12 lb range.
Walmart itemEstimate uses the midpoint of a 32-64 oz weekly range and the average Walmart pH up/down ounce cost.
pH down pH upSmall 4 lb bag is $19.97, or about $4.99/lb. Estimate uses 3 lb/month.
Walmart itemBasic Service includes testing and adding 7 chemicals, checking equipment, skimming the surface, netting the bottom, brushing walls and steps, cleaning tile, and monthly filter cleaning for $110/mo.
That means the chemical cost alone can be about $39 more than Basic Service every month, before counting your time, fuel, testing, storage, and the work of cleaning the pool.
Chemicals only. You still test, dose, brush, skim, clean the filter, and handle the pool.
$148.68 DIY chemicals minus $110 Basic Service is about $38.68 saved each month, while Oasis handles the weekly service work.
That is before counting testing, dosing, brushing, skimming, filter cleaning, storage, and supply runs.