Same Brand Thermometers, Different Readings

[celaeno]

so i was at the lfs today... i saw two submersible thermometers that were exactly the same with readings that were different by 4F. one read 69F, the other read 73F.

it was a hagen/marina thermometer. this makes me cautious about buying their thermometers.

 

[tmack]

Were they in the same tank?

 

[demonmagus]

I would think so, otherwise the thread would make no sense lol

 

[celaeno]

they weren't in a tank, they were hanging next to each other on the shelf.

 

[DiscusAngel]

lol but there coud have been someone holding it before?

 

[celaeno]

Get the glass thermometers instead of the magnetic(???) strip ones. They're more accurate.

this is the thermometer with the issue... http/www.walmart.com/catalog/product.do?product_id=3635079

 

[SuperColey1]

I bought one of these (exactly same make and type) as they're floating and I could float it in my water change tap water until it was right (used to be a lot more finnicky about matching temps than now)

Question......are they supposed to be safe for leaving permanently inside the aquarium?

Word of warning!!!!

I used to stick mine by the sucker against the wall in my kitchen (under the cupboard where all my fish bits are) normal temp (UK) probs average 26-27 (tank temp)

Came into the kitchen one morning and the bottom had exploded leaving a fluorescent pink drip all down the wall and a puddle on the work surface.

Apart from the permanent stain it has left behind, thank god I didn't use it in the aquarium.

 

[celaeno]

Came into the kitchen one morning and the bottom had exploded leaving a fluorescent pink drip all down the wall and a puddle on the work surface.

Apart from the permanent stain it has left behind, thank god I didn't use it in the aquarium.

that's very reassuring... so which suction cup internal thermometer do you guys recommend?

 

[clareriley]

I use digital ones but before I got these I used the bogstandard glass aquarium ones from any lfs.

 

[Davey Jones]

Came into the kitchen one morning and the bottom had exploded leaving a fluorescent pink drip all down the wall and a puddle on the work surface.

Apart from the permanent stain it has left behind, thank god I didn't use it in the aquarium.

that's very reassuring... so which suction cup internal thermometer do you guys recommend?

I have a standard glass one & a submersible digital one...i'm not paranoid, really

 

[SuperColey1]

I have no thermometer inside the tank

I have black stick to the tank one on the outside of the tank - it says 26

I also have a very reliable........................thermostat in my house set to 26. lol

Surely the water in the tank will be the same temp as the air around it

 

[clareriley]

I have no thermometer inside the tank

I have black stick to the tank one on the outside of the tank - it says 26

I also have a very reliable........................thermostat in my house set to 26. lol

Surely the water in the tank will be the same temp as the air around it

Nope, not at all, I used to have a black strip and it used to say 26.. then i got a glass one for the inside and the inside was 24. I then got glass ones for all my tanks which had the strips and they were all 2degs colder on the glass ones. so then I got digital and glass and the temps were the same so now I am against the strip and all for digital but if you cant afford then glass.

 

[chibi]

I don't like those strip thermometers. I find them hard to read. I had the thermometer you showed for almost two years before the suction cup bit the dust. Nice little thermometer. One may be broken. I'd get a new one and compare it to the two you have now. One is bound to be a bit messed up.

 

[tmack]

I would think so, otherwise the thread would make no sense lol

I've learned to never assume!

I prefer the digital ones with a probe in the tank and a wire to the numerical readout on the outside of the tank. Got mine for $10 at a Petco near me, and even checked it vs. a thermometer in the lab at work & it was right on!

 

[Tolak]

I buy the cheapest thermometers; http/www.bigalsonline.com/BigAlsUS/ctl36...teelthermometer


They all vary, plus or minus 3F. They also react almost instantly to temperature, great for water changes where I'm hosing water into the tank, and want to hold or vary the temp.

Being cheap, I callibrate them with my one good thermometer, a labratory grade mercury one. I scratch +2, -3, or whatever on the back. I don't worry about dropping & breaking them like an expensive thermometer. I can check the temp of every tank without worrying about cross contamination.

The floating ones are more accurate, but take longer to react to a temperature change. I make a habit of putting my hand on the outside of every tank when I'm feeding, you can tell if it's way too warm or cold in a second. If something seems out of wack I check with a cheapie.