Review on Stay Informed About Water Temperature With Blufree Floating Pool Thermometer - Perfect For Pools, Baths, Spas, Hot Tubs, Aquariums & Ponds by Adam Gardner

Update: after only 3 months or so, in addition to the problem below, the thermometer tube inside the outer tube became unglued and just flops around inside the clear protective tube, making it worthless. Tube is not broken, just unglued or un-fastened. It was not dropped as it was tied to a nearby air knob and all maintenance is done by one person, so it is a complete fail. A suggestion: in a clean hot tub, chemically balanced and not displaying any sediment, algae, etc., this blue rubber float portion still gathers a 'slime' or scum layer for some reason. The same isn't visible on any other spa devices, walls or filters. The layer rubs off but leaves a slight stain. Our suggestion is to use a less porous, more cleanable or slick float surface that is less likely to develop this problem.