North Sanctum
A hot tub in a finished basement in winter, its cover parked upright beside it, a blue bubble blanket on the water and a small sensor on the wall
Hot Tubs XY-WQ

XY-WQ Puffer Floating Pool Thermometer with String, Easy-Read

A battery-free floating thermometer that gives a second reading next to the tub's own display.

Best for checking the water before getting ina second opinion on the control panelnoticing a heater that is falling behind

A tub’s control panel shows what the heater’s sensor reads. A separate thermometer in the water shows what the soaker will feel – and in winter it is the simplest way to notice a heater that is slowly falling behind. This one is a plain liquid-column thermometer, 8.5 in (21.6 cm) long, hanging under a blue puffer-fish float, with a scale that runs to 120 °F (50 °C).

There is nothing to charge or pair. There is also no stated accuracy and no alert, so read it as a check on the panel: if the two disagree by more than a couple of degrees, that is worth a look at the manual.

Tip: Tie the string to a cover strap or handle, and read it before you get in – after the jets have run for a minute, so the water is mixed.

Photos & price on AmazonAffiliate link

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