# I put 3 ADA thermometer into same tank- you won’t believe what happened next



## Jack Reilly (22 Jul 2018)

One reads 24 one reads 22 and one reads 21. I left them in there for half an hour, gave them all a gentle tap with finger etc but their readings are steady. I even held the two smaller ones lower in the tank to see if that accounted for the difference but it didn’t. Isn’t this a lot of variation amongst the same thermometers? I run my tanks at 24 so if it’s in fact 21 that’s pretty chilly.... how do I know which one is accurate ?


----------



## Edvet (22 Jul 2018)




----------



## Nigel95 (22 Jul 2018)

Meh didn’t expect that tbh…


Verzonden vanaf mijn iPhone met Tapatalk


----------



## J@mes (22 Jul 2018)

I’d say you have to assume none of them are accurate and work out the average and use that.


----------



## FJK_12 (22 Jul 2018)

slightly concerning - perhaps it is a problem with traditional thermometers as opposed to ada? Im clutching at straws here but don't want to think that mine is wrong. Maybe someone can test wit other brands?


----------



## tam (22 Jul 2018)

Are the two on the right next to each other? It's probably perspective but the gauge marks look different. Are you sure they are all genuine?


----------



## techfool (22 Jul 2018)

Like test kits thermometers aren't accurate but I use them as a guideline. The difference between 21 and 24 won't matter to your plants. Some fish may find it chilly. You can tell by observation. Or putting your finger in the water.
I think mercury is more accurate but we don't use that anymore.
I got five thermometers from china that were super cheap and seem okay. They are all measuring the same within 1 degree - none of the tanks have heating atm because of our unusually warm summer.
My digital room thermometers differ by up to 5 degrees ! 
Medical thermometers must be more accurate but no need for them to measure that low.


----------



## Edvet (22 Jul 2018)

I actually use a lab themometer if i want to know the temp, just hold it in there 10 secs and read it.


----------



## sparkyweasel (22 Jul 2018)

I use a lab thermometer to check the cheap ones in my tanks are ok. 
Also, when you buy, look at a few on the rack in the shop, if they all read the same, they are probably right. If one's different, don't buy that one, if they're all different, don't buy any of them. 

btw, don't you hate it when you splash out on a big-name brand thinking you'll get something a bit special and it's not as good as the cheap and cheerful stuff you normally buy? It's happened to me a few times. lol.
Have you bought these recently? If so, you should take them back and see what the seller says.


----------



## Jack Reilly (22 Jul 2018)

tam said:


> Are the two on the right next to each other? It's probably perspective but the gauge marks look different. Are you sure they are all genuine?


I can only assume they are genuine. They’re all bought from proper Retailers. The one on the right does look slightly off centre but that could just be a normal variation. None of ADAs glassware is identical from what I can tell once you look closely enough.


----------



## Jack Reilly (22 Jul 2018)

sparkyweasel said:


> btw, don't you hate it when you splash out on a big-name brand thinking you'll get something a bit special and it's not as good as the cheap and cheerful stuff you normally buy? It's happened to me a few times. lol.
> Have you bought these recently? If so, you should take them back and see what the seller says.


Not recently so I can’t return them. I might contact ADA directly for response. And yes I do hate that. For instance I bought the most expensive co2art regulator and it’s currently sitting in a box in the cupboard because the solenoid keeps not turning off and the pressure isn’t consistent.  I’m back to using the cheap Chinese one it was replacing. Now I have a dupla one in the mail which is even more expensive.


----------



## Majsa (22 Jul 2018)

I don't trust the tank thermometers so I use this one from my baking gear once in a while, especially for WCs. Not sure if it's accurate but good for a lot of purposes


----------



## mort (22 Jul 2018)

If you get a glass of water and put a lot of ice in it then after a few minute it's will be 0c, you can then add the thermometers and see which reads zero.  Unfortunately that type of thermometers often needs a calibration amount added to the reading. I have one (not ada but identical) and know after the water test that I need to add 2c. You might be lucky and find you have one spot on.


----------



## ian_m (23 Jul 2018)

Perfectly acceptable your readings. A typical "liquid in glass" thermometer will have ±2°C accuracy, all of those are within acceptable readings.

You have to start paying a lot more and/or having greatly restricted range if you want much more accuracy than this.

Mind you I would have thought ADA cost would be for ±1°C accuracy, but clearly not.


----------



## Bolota (23 Jul 2018)

I would try to put them all underwater in a bath at the same level. To begin with you never know if the temp your tank is totally homogeneized. also you have a significant part of the glass out of the water. That may also affect your experiment. 
finally there is the accuracy issue already mentioned.


----------



## Jack Reilly (24 Jul 2018)

I had a response from ADA, they said there thermometers should be accurate within 1 degree.


----------



## Jack Reilly (24 Jul 2018)

Bolota said:


> I would try to put them all underwater in a bath at the same level. To begin with you never know if the temp your tank is totally homogeneized. also you have a significant part of the glass out of the water. That may also affect your experiment.
> finally there is the accuracy issue already mentioned.


Thats what I thought too so I did put the other thermometers deeper in the water but they didn't change temperature.


----------



## Edvet (24 Jul 2018)

The melting ice is 0 degrees will be a nice test. With pics of course


----------



## zozo (24 Jul 2018)

Jack Reilly said:


> I had a response from ADA, they said there thermometers should be accurate within 1 degree.



That's their response after seeing that picture?. They are clearly not...


----------



## kadoxu (25 Jul 2018)

zozo said:


> That's their response after seeing that picture?. They are clearly not...


They did say "should"!


----------



## Jack Reilly (29 Jul 2018)

It appears after using the ice method and also comparing to indoor digital thermostat that the large ada thermometer reading 24 is actually the correct reading, while 21 and 22 are way off.


----------

