Marina Floating Thermometer

A free-floating glass thermometer is the one to pick when you want the reading to travel — between a quarantine tub, a bucket of fresh water and the display tank — rather than being committed to one pane of glass.

Key features

• Floats upright in the water, or attaches inside the tank with a suction cup if you would rather it stayed in one spot.
• Reads in both Celsius and Fahrenheit, with a marked comfort band for tropical fish.
• A glass column sits in the water itself, so it reads more truthfully than a strip stuck to the outside of the pane.
• Several versions, including a larger easy-read size — see the selector for what is in stock.

It earns its keep at water change time: check the tank, then check the bucket before anything goes in. Suction cups perish and eventually let go, so glance at yours now and then rather than trusting it indefinitely. Our other Marina thermometers include a clip-on stainless model and adhesive LCD strips.