Aquatop ATSD-01 Stick-On Digital Thermometer

The Aquatop ATSD-01 Stick-On Digital Thermometer is the no-fuss way to watch tank temperature without putting anything in the water. Peel the backing, press the 1 x 2.5 inch strip to the outside of the glass, and the liquid-crystal scale lights up the current temperature from 64 to 86 degrees F with a green line marking the range most tropical fish prefer. Nothing to float, nothing to break and no batteries. It suits freshwater and saltwater tanks alike, and it is a handy second opinion next to your heater's dial. Browse the rest of our water care and monitoring gear.

Why You'll Love It

• Nothing inside the tank: mounts on the outside wall, so it never gets knocked loose by fish or buried during a water change.
• Read it from across the room: the active segment lights up in color against the black strip.
• Green safe zone: a quick glance tells you whether the tank is holding in the tropical range.
• Compact: at 1 x 2.5 inches it fits a betta cube or a nano reef without cluttering the view.
• Fresh or salt: it never touches the water, so it works on any aquarium.

How to Use

1. Clean and dry a spot on the outside of the glass, below the water line and away from the heater, lights and direct sun.
2. Peel the backing and press the strip firmly onto the glass.
3. Give it a minute to settle, then read the segment that shows in color. If two segments show, the temperature is between them.
4. Re-stick to a fresh spot if algae or condensation builds behind it.

Specifications

What's Included

• 1 Aquatop ATSD-01 stick-on thermometer strip

Recommended Pairings

• Aquatop GT-001 Floating Glass Thermometer, an in-tank glass thermometer with suction cup
• Aquatop AWAT-001 Weighted Glass Thermometer, the sinking version with a claw base
• Aquatop Smart-Temp Thermometer, a magnet-mount digital readout
• Aquatop Pisces 25W Nano Heater and Pisces 10W Nano Heater, pre-set heaters for small tanks
• More water care and monitoring gear

FAQ

How accurate is a stick-on strip? It reads the glass, which tracks the water closely on a small tank, and it is accurate enough to confirm the heater is holding in the safe zone. For an exact number, pair it with an in-tank thermometer.

Will it work on acrylic? Aquatop specifies glass aquariums. It will stick to acrylic, but the reading can lag because acrylic insulates more than glass.

Can I move it? The adhesive is meant for a single placement. Choose the spot carefully; it may not re-stick well after removal.

Why does it read low near the top of the tank? Evaporation cools the glass near the surface. Mount it a few inches below the water line for a truer reading.