Pool and hot tub help, in plain English

Calculators that show their working, buying guides built on published specs and prices, and straight answers to the problems that turn up every season. Written for US owners, in gallons and °F.

Calculators

• Pool volume calculator

  How many gallons your pool holds: rectangle, round or oval, with a shallow and deep end.

• Pool salt calculator

  Pounds of salt to reach your chlorinator's target ppm, with the volume worked out for you.

• Hot tub running cost

  What your hot tub costs in electricity each month, using your own rate per kWh.

Pools

• Best robotic pool cleaner

  Corded and cordless models compared on runtime, what they clean, pool size and warranty.

• Aiper vs Beatbot

  The two cordless brands side by side, model against model at each price.

• Best pool test kit

  Drop kits, strips and digital testers: what each one measures and how precisely.

Hot tubs

• Why is my hot tub water cloudy?

  The usual causes, how to tell which one you've got, and the fix for each.

• Chlorine vs bromine

  Which sanitizer suits your tub, what levels to keep, and how to switch safely.

• Monthly running cost

  Where the electricity goes and the cheapest ways to cut it.

How this site works

Tub & Pool is a small independent site run from the UK, written for pool and hot tub owners in the US. We haven't tested the products we write about, and we won't pretend to. Buying guides compare what manufacturers publish and what things cost, and every page lists its sources with the date they were checked.

Chemical advice follows the CDC's Healthy Swimming guidance and the product label. If a page and a label ever disagree, the label wins. More on the About page.