suction cup thermometer vs. outside stick on thermometer!

[allaboutfish]

which is better.
suction cup

stick on

 

[fort384]

Moved to General Hardware and Equipment Discussion.

Neither is better. Whatever you like is fine. I have 1 of each between my 2 tanks I am currently running.

 

[rich311k]

I agree does not much matter. Which ever you like is fine.

 

[mfdrookie516]

I think the in tank thermometers are better, simply because the glass can be warmer or cooler than the water if the ambient room temp is off by much.

 

[fort384]

It might be off by a degree or 2, if there was an extreme difference in the temp of the tank vs. the room, but I doubt it. Water is a far better conductor of heat than air, so the glass is going to be almost the identical temperature of the water inside, not the ambient temperature of the air.

 

[HUKIT]

The in tank thermometers are more accurate.

 

[Cdepriest6009]

I have one of each on my 25 and they are on opposite sides of the tank and always read the same thing. The only difference is with the in tank ones you can see the exact tally marks of the mercury but mine never changes unless I'm doing water changes.

 

[allaboutfish]

the in tank ones are harder to see the temp though that's what i was trying to see if the outside ones were still as good.

 

[Fishguy2727]

I like JW's inside magnet mounted thermometer or the electronic ones with a probe inside the tank and a display outside.

I would only get the outside thermometer if you want to know the average of the tank and room at best.

Water is a great insulator of heat, not conductor of heat. It holds on to it very well.

 

[fort384]

What I said is correct, and the outside thermometer is in NO way an average of the tank and room. Water is a far better conductor of heat than air. I didn't say it was a great conductor. I said it is far better than air.

 

[Fishguy2727]

But the stick ong thermometers dpn't evan touch the water. The real question would be how well glass conducts or insulates heat.

Don't buy a stick-on thermometer, no reason to when there are multiple options that actually touch the water.

 

[shammond15731]

I also have one of each at opposite ends of my 30 gallon long tank and both readt the same as each other all the time. They are cheap enough I say buy one of each and see for yourself which you prefer, I mean it has to be the cheapest thing you can buy for the tank.

 

[jcolon]

But the stick ong thermometers dpn't evan touch the water. The real question would be how well glass conducts or insulates heat.

Don't buy a stick-on thermometer, no reason to when there are multiple options that actually touch the water.

From a science teacher's perspective ... the suction cup thermometer will be more accurate because it's in direct contact with the water. Naturally the stick on is really reading the glass temperature ... which in most cases will be close to the water temp .. but will be slightly off.

Heat travels from warm to cool, and glass will conduct this heat back and forth. If the outside air temp is warmer than your aquarium, the heat is conducted from the air through the glass into your water ... so at that point it the stick on is really reading the outside glass temp more than the water temp, When the aquarium is warmer, the stick on is reading more of the water temp.

For what it's worth ... I just have the stick on that came with the tank ... It's close enough since we keep the ambient air at a stable temp.

 

[Cdepriest6009]

I would just go with the stick on they are easier to read and there is not enough of a difference to matter. It's not like you have to have the temp at exactly 78 or your fish will die.

 

[allaboutfish]

k thanks everyone ill get a stick on bc i like how theyre easier to read but ill put my current suction cup one on every now and then to make sure it's accurate.

 

[fort384]

It will be accurate. No reason to worry. Stick on thermometers work just fine.

 

[roydooms]

I have 3 types of thermometers n my 125g and they all read the same temp.

 

[fort384]

But the stick ong thermometers dpn't evan touch the water. The real question would be how well glass conducts or insulates heat.

It isn't about the glass at all. The glass is the only thing constant. It is what is better at transmitting heat to the glass - the ambient air, or the water inside. Based on thermal dynamics, it's the water (like I said, water is a better conductor of thermal energy than air).

 

[fort384]

In case further proof is needed, who are 2 photos taken within seconds of each other, just now.

The first, the stick on thermometer is registering 74F

The second, an in tank thermometer, is registering 73.5F

Sorry, I know the quality isn't good... but as you can see, the thermometers register almost the identical temperature (within ½ of 1 degree).

 

[BeavisMom62]

I don't like the stick on kind. I've never had any luck with them. But I also have no luck with the inside tank thermometers either. Only a few of mine are accurate, even if they are the same brand! I need to invest in more expensive ones one of these days. Mostly, I use my hands!