# Cracked thermometer. Mercury hazard?



## AquaNeko (Jul 26, 2009)

Ok, I have no idea how the thermometer got cracked. Loved this thermometer from PetsMart as it was more graded on the C side then F for quick reading. 

My thermometer placement is about 2in from the heater. I have a 50W heater in a 10gal std tank. This is a glass thermometer which I placed in the back of the tank and rotated the thermometer so that thermometer is facing the front of the tank while the suction cup is facing the back unlike the original stock config. in the packaging. 

I have been using the thermometer in this setup with no cracks for well over a year since I got the tank. I'm not sure how the top of the thermometer on the curve it got cracked. I am seeing a slow leak of water into the thermometer. I'd say 1/2 inch of water inside the thermometer after a month in the tank. 

It appears the mercury is in a seperate glass enclosure so I'm not sure if it is leaking mercury or not. I don't see any cracking in the mercury area just the outter curve of the thermometer. 

Is this ok to keep on using if there is no mercury leak?


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## Fish_Man (Apr 9, 2010)

They don't use mercury in aquarium thermometer anymore. Mercury is a silver metal, so you can tell by looking at it if it contains mercury, If it's any other colour, red, green etc, then it's a non-toxic oil and dye.



AquaNeko said:


> Ok, I have no idea how the thermometer got cracked. Loved this thermometer from PetsMart as it was more graded on the C side then F for quick reading.
> 
> My thermometer placement is about 2in from the heater. I have a 50W heater in a 10gal std tank. This is a glass thermometer which I placed in the back of the tank and rotated the thermometer so that thermometer is facing the front of the tank while the suction cup is facing the back unlike the original stock config. in the packaging.
> 
> ...


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## AquaNekoMobile (Feb 26, 2010)

Fish_Man said:


> They don't use mercury in aquarium thermometer anymore. Mercury is a silver metal, so you can tell by looking at it if it contains mercury, If it's any other colour, red, green etc, then it's a non-toxic oil and dye.


Thanks. I'll check again when I'm home. Now that I think about it I think there was some silver something or lead shot inside the thermometer and the liquid was red.

The thermometer was purchased about 2 yrs ago.


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## Riceburner (Mar 14, 2008)

the liquid is in a separate tube. Then inside the outer case that has the metal beads for weight. I've had a few break. No biggie...just get the broken bits out.


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## characinfan (Dec 24, 2008)

In the event that it is mercury, you shouldn't throw it out in the normal garbage. Put it in a ziploc bag and take it to the hazardous waste depot.


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## AquaNekoMobile (Feb 26, 2010)

What test can I do to be absolutely sure there is no mercury in the water?

Like with household items or what should I look for as signs of mercury issues?


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## bob123 (Dec 31, 2009)

They don't use mercury in aquarium thermometers, I wouldn't worry about mercury in the water.


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## Kerohime (Jan 10, 2011)

If it has metal beats at the bottom tip and red liquid in the indicator meter its probably something else, not mercury. 

I broke one of these in the lab and my supervisor told me not to worry about mercury.


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## chriscro (Dec 3, 2010)

you can replace it for $3..... why take the risk????


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## Lee_D (Jun 11, 2010)

If it is red, then it is alcohol based. There is no mercury in it. If your still concerned, I can sell you a Mercury analyzer for 40 grand.


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## qwerty (Dec 15, 2009)

I would replace it just cause thermometers are pretty cheap, and if it's cracked then it's more likely to break, resulting in bits of glass in your tank.

But as everyone has said I personally wouldn't worry about mercury.


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## mrobson (Mar 5, 2011)

i agree they havent used mercury in that type of thermometer for years, if it was leaking you would probably know by now.


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## KhuliLoachFan (Mar 8, 2008)

I used to work for a company that sells mercury analyzers. I think we can get you one for only $25K. 

I can pretty much guarantee you that NO mercury thermometers have been sold in the aquarium trade in Canada in the last 20 years.

All your fluorescent light fixtures have mercury vapor in them. If you have an old mercury-bubble-style thermostat in your house, that's another common place to find it. I think that's it for common household sources.

Those little round balls at the end of the thermometer are not even lead. They are just a rather dense metal alloy, that is used as a lead-free weight alternative, to keep the bottom of the thing from floating up to the top on you, which is really annoying.

W


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## Lee_D (Jun 11, 2010)

Actually I don't sell the Mercury analyzers, I just occasionally fix them, so I'm likely off on the price.

As for Mercury, I'm not sure of the regulations, but I think it was banned back in the seventies. It was one of the early toxins that governments started looking at. The paper industry was putting tons of it in the rivers back then. Probably from the bleaching process.

Lee


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