You want to keep it blue, the one in the middle. Mr. Beer sells stick on thermometers (not that useless sticker) for $1.95. Better to get a $10 aquarium digital thermometer and tape it on, then you get actual degrees. How do I read the stick on Thermometer... Can't find any info. I'm fixing to order a couple stick-ons from MRB, but what I really like are those in the pictures earlier in this thread. I just happen to have things fermenting right now. I have 2 colors showing all the time...the blue one and the top brown one. I just received a new LBK and no thermometer. Like one bracketed range for lager, one for ale, etc. If you have a Meat Refrigerator Pool Oven  you can use this - it goes way high up there. I know this is an old thread, and I hope the OP is no longer confused, so....... Mr Beer, why don't these little 3-position thermometers NOT come with the LBK any more? Stick on thermometers are the most widely used thermometer in freshwater aquariums as they are often provided as part of the new aquarium package. Assuming the heater works, set it so it just comes on, and monitor the temperature on an accurate thermometer. Does it need to be at approx. So since I needed items from both, I went ahead and ordered both. Our free guide can help keep your tank clean and your fish healthy. I now have 6. $10 aquarium thermometer? Dr. Nick Saint-Erne has worked in veterinary hospitals treating a variety of animals, including zoo animals and exotic pets for over 35 years. If you have to contort your body just to see the thermometer, it's not in an ideal location. By I wouldn't think many in here need those, but they're good for me so I can learn those particular basics. They are usually referred to as LCD (Liquid Crystal Display) thermometers and sometimes called "digital" thermometers, which is not fully accurate. Yea I saw that I think it was suppose to read. Hi @TBONE 69, great question. A few models place both the sensor and display inside the tank. Possibly the biggest downside of these type is the fact that most are made of glass, and thus are more fragile than other types. I love that place so much. If your tank has large boisterous fish, this is not a wise choice for a thermometer. But it may not be more accurate, it just implies that it is . Sign up for a new account in our community. Many have dual Fahrenheit and Celsius scales, while some have a single scale in larger numbers. An aquarium thermometer is inexpensive and usually much more accurate than the thermostat on an aquarium heater. $10 aquarium or "ray gun" thermometer is battery operated with digital readout. To see if the heater is working, put it on a high setting then feel it. Some connect wirelessly, while others have a cord that physically attaches the probe to the display. Rite brew is the shiznit. Make sure that the surface is dry as well. The Rite Brews were 1.99 but the nice thing about them is they are 8" and like the thermometers above that show the bracketed temperature ranges for each beer style. But it may not be more accurate, it just implies that it is I did have the $1.95 (now on sale for $1.45!!) There are three basic types of aquarium thermometers: stick on the outside, float/standing in the water, and digital meters. If you have a Meat Refrigerator Pool Oven  you can use this - it goes way high up there. This is the one I use, works great, and very accurate. Although the tank may look fine, changing or unsuitable water temperature can have a negative effect on both fish and plants. To me, the difference in a degree doesnt bother me. @TBONE 69 I'd just add that it's better to be a bit on the cool side than too warm, so even showing both I'd be okay with that on my fermenter.