Description
Glass Aquarium Thermometer BT-01 — Accurate Dual-Scale Temperature Monitoring for Any Aquarium
Glass Aquarium Thermometer BT-01 is a classic, reliable glass thermometer designed for accurate temperature monitoring in freshwater and saltwater aquariums of all sizes. Glass Aquarium Thermometer BT-01 displays temperature simultaneously in both Fahrenheit and Celsius on a clearly marked glass scale — covering the full 30–110°F (0–40°C) range that encompasses all freshwater tropical fish, coldwater species, reef aquariums, and marine fish-only systems. A green safety zone indicator on the scale provides an at-a-glance reference for the ideal temperature range for most tropical freshwater fish, making it easy to confirm tank temperature is within acceptable parameters without consulting a chart. The included suction cup mount secures Glass Aquarium Thermometer BT-01 to the inside of the aquarium glass in seconds, holding the thermometer in place at all times for consistent, reliable readings whenever you check the tank. Manufactured by BOYU.
Key Features of Glass Aquarium Thermometer BT-01
- Dual-scale display — reads temperature simultaneously in both Fahrenheit (°F) and Celsius (°C) on a single clearly marked scale
- Temperature range 30–110°F (0–40°C) — covers all freshwater tropical, coldwater, reef, and marine aquarium temperature requirements
- Green safety zone indicator — visual reference band marking the ideal temperature range for most tropical freshwater fish
- Fully sealed glass construction — completely leak-proof; will not cloud or discolor over time like plastic thermometers
- Suction cup mount included — secures thermometer to the inside of aquarium glass for stable, continuous placement
- Slim, elegant design — compact profile minimizes visual impact inside the aquarium
- Compatible with freshwater and saltwater aquariums
Glass Aquarium Thermometer BT-01 — Placement Guide for Accurate Readings
For the most accurate temperature readings from Glass Aquarium Thermometer BT-01, position the thermometer away from direct sources of temperature fluctuation — do not place it immediately adjacent to the heater element, filter outlet, or surface agitation from a powerhead. Position it in an area of stable, ambient water circulation — typically the midpoint of the aquarium at mid-depth. This ensures the thermometer reads the true average ambient tank temperature rather than a localized hot or cold zone.
Glass vs. Stick-On Thermometers
Stick-on external thermometers measure the temperature of the glass rather than the water itself — influenced by ambient room temperature, direct sunlight on the tank, and the thermal properties of the glass. Glass Aquarium Thermometer BT-01 measures water temperature directly from inside the tank, providing a significantly more accurate reading of the actual conditions your fish and invertebrates are experiencing. For any aquarist who relies on accurate temperature data — particularly reef hobbyists, breeders, and keepers of temperature-sensitive species — an in-tank glass thermometer is the minimum reliable standard.
Technical Specifications
Glass Aquarium Thermometer BT-01 is manufactured by BOYU and distributed through JBJ Aquariums.
| Brand | BOYU |
| Model | BT-01 |
| Type | Floating glass thermometer with suction cup |
| Temperature Range | 30–110°F (0–40°C) |
| Scale | Dual — Fahrenheit and Celsius |
| Safety Zone Indicator | Yes — green band for tropical fish range |
| Construction | Fully sealed glass — leak-proof |
| Mount | Suction cup — inside glass placement |
| Compatible With | Freshwater and Saltwater Aquariums |
| UPC | 6924781200791 |
| SKU | BT-01 |
| Price | $2.99 |
For precision digital temperature control, browse our JBJ TrueTemp Titanium Heaters — available from 100W to 800W with ±0.5°F digital accuracy for aquariums from 20 to 260 gallons. For more aquarium accessories, visit the JBJ Aquariums thermometers page.





