Got a stick-on thermometer

[IndiaHawker]

Been using the glass sucker one that came with my tank, but it's so hard to read (I have good eyesight but even I struggle to read it) and I kind of like the nostalgia of the stick-on kind - my mum adopted a large aquarium at some point in my childhood which had a stick-on thermometer and I just liked it Plus the glass one keeps coming loose, gets in the way visually, and builds up algae.

My really stupid question: When I stick the thermometer on, does it matter if I stick it right to the bottom of my tank, so the substrate will be 'covering' the bottom part? I imagine the substrate will only reach up to about 20c or so so either way it shouldn't affect it? But I'd like to know, and for future reference as well! Please and thanks

 

[Essjay]

Do you mean one of those flat strips like this that change colour with the temperature? They are not as accurate as the glass ones that go inside the tank because they are in contact with the air in the room rather than with the water inside the tank. If you do use the stick on LCD type thermometer on the outside, it should not overlap the substrate.

The most accurate, and most expensive, type of thermometer is the digital type with a probe that sits inside the water and has a display screen outside the tank

 

[seangee]

The most accurate, and most expensive, type of thermometer is the digital type with a probe that sits inside the water and has a display screen outside the tank

I've had great results with the not so expensive ones. I have 6 of these https://www.amazon.co.uk/gp/product/B01N1ZLR8T/?tag= (one even lives on my motorcycle ) and they are all within 0.1C of each other.

On the Flex it means I can have the probe concealed in the back with display on the side of the tank.

 

[NickAu]

Those thermometers are perfect Seangee.

 

[Byron]

I agree with essjay on the accuracy risk of the "stick on," I was into these many years ago and found some variation. I changed to the floating that you can stick on the glass, though I agree with your comments about them. But they are reliable (or should be). The digital probes I have not used, though I have one built in to my Eheim Pro 2 canister (it has the heating element) and this has been ideal in all respects.

One thing to keep in mind though is the placement of any of these in the water column. Never close to the substrate as the water there is always colder. Never right at the surface as the water there is always warmest. In the upper half of the tank is best. And never close to the heater.

I use the floating thermometers now as I said, and I stick them in one of the front corners near the surface so the bottom of the thermometer is 4-5 inches below the surface. Given the normal thermal currents, and provided this is not next to the heater, you should get a good mid-range reading sufficient to set the heater temperature. The substrate water will be cooler as I said, but that is normal and fish can deal with it.

 

[Fishmanic]

I have used all three types of thermometers...digital, glass tube type, and stick on tape type. I found the stick on to be fairly accurate on my glass tanks as I compared it to the tube type. But the best thermometer to get is the digital type...easy to read, accurate, and very inexpensive..just a few dollars if ordered from china. Batteries last a very long time...like years. I use the digital type on all 3 of my tanks now.

 

[Kimm87]

I have all 3 types on my unheated 5 g. I have the strip type right at the bottom corner and they all seem relatively close in temp, but since the tank isnt heated it may just be an ambient room temp. I bought the digital thermometer on ebay for like $2 it takes a button cell battery that i also had to buy.