Marina Floating Glass Thermometer
A simple glass thermometer that floats or sticks to the glass.
The Marina Floating Glass Thermometer is a liquid-filled glass thermometer for freshwater and marine aquariums. It's designed to float upright in the water, and comes with a suction cup so you can fix it to the inside of the glass instead if you'd rather it stayed in one spot.
Key features
- Dual scale — reads in both Celsius and Fahrenheit, so you can check the temperature at a glance.
- Safety zone band — a marked zone on the scale shows the general temperature range suited to most tropical fish.
- Float or stick — works loose and floating, or held against the glass with the included suction cup.
- Fresh or marine — suits both freshwater and saltwater aquariums.
Specifications
| Spec | Detail |
|---|---|
| Brand | Marina (Hagen) |
| Type | Liquid-filled glass thermometer |
| Mounting | Floats freely, or suction-mounts to glass |
| Scale | Celsius and Fahrenheit |
| Water type | Freshwater and saltwater |
| SKU | AA3821 |
Hagen does not publish an exact numeric temperature range for this model — the scale carries a marked safety zone rather than printed minimum and maximum figures.
Suitable for, and not suitable for
- Everyday temperature checks in freshwater and marine tanks.
- Not a substitute for a digital controller probe if you're relying on the reading to run a heater or chiller automatically — this is a visual, check-by-eye thermometer only.
Care and maintenance
Wipe algae off the glass occasionally so the scale stays easy to read. Being glass, handle it gently — it isn't a scraper for the tank.
Goes well with
- A digital thermometer or controller, if you want a continuously logged reading rather than a glance-and-check one.
- An algae scraper, for keeping the glass around the thermometer clean.
Warranty and delivery
Covered by Marina's standard warranty against manufacturing defects, in addition to your rights under the Australian Consumer Law. Standard freight applies.
Common questions
Does it need to float, or should I stick it to the glass?
Either works. Floating is simplest; the suction cup is there if you'd rather it stayed in a fixed viewing spot.
Will it work in a saltwater tank?
Yes — Marina markets this thermometer for both freshwater and saltwater use.
How accurate is the safety zone marking?
It's a general guide to the range most tropical fish are kept in, not a precise reading — for critical applications, pair it with a digital thermometer.
