Tank Temp, Are the On Board Temp Sensors Accurate?

[Uncle99]

My DT has run at 77.7 to 78.3 for years. I test with 3 different digital temperature probes and one glass thermometer to calibrate my controller. Each provides a consistent read of 78.1-78.3.

As a matter of safety, my two 300watt current heaters are two years old, so I replaced them.

I bought two 300 watt Aquarium Masters digital heaters which claim high degree of accuracy.
Each was $100 bucks.

Both indicate the DT water is 81 degrees.

Both off 3 degrees. Wow!

If I didn’t know the water temp before trying, I would have thought this was correct. Not 1 incorrect, but both by the same amount.

Beware.

 

[EeyoreIsMySpiritAnimal]

My DT has run at 77.7 to 78.3 for years. I test with 3 different digital temperature probes and one glass thermometer to calibrate my controller. Each provides a consistent read of 78.1-78.3.

As a matter of safety, my two 300watt current heaters are two years old, so I replaced them.

I bought two 300 watt Aquarium Masters digital heaters which claim high degree of accuracy.
Each was $100 bucks.

Both indicate the DT water is 81 degrees.

Both off 3 degrees. Wow!

If I didn’t know the water temp before trying, I would have thought this was correct. Not 1 incorrect, but both by the same amount.

Beware.

Are there instructions for calibrating the new heaters?

 

[Sean Clark]

Trust but verify. I recently discovered that my temp probe was reporting 4.1deg F high.

 

[Uncle99]

Are there instructions for calibrating the new heaters?

Cannot be calibrated.
That would have been at least, helpful.

 

[Uncle99]

Trust but verify. I recently discovered that my temp probe was reporting 4.1deg F high.

I agree. I just thought they would be closer than 3 degrees out (and in your case 4 degrees) when used in a hobby that requires accuracy.

Aquarium Masters Smart Temp is sold as a “top of the line” heater “accurate to +- 1%.” And is twice the price of other heaters.

“top of the line”……is a NOT.
“accurate”……is a NOT.

Should have just stayed with the Eheim Jager for half the price.

 

[Sean Clark]

I agree. I just thought they would be closer than 3 degrees out (and in your case 4 degrees) when used in a hobby that requires accuracy.

Aquarium Masters Smart Temp is sold as a “top of the line” heater “accurate to +- 1%.” And is twice the price of other heaters.

“top of the line”……is a NOT.
“accurate”……is a NOT.

Should have just stayed with the Eheim Jager for half the price.

And then you could calibrate it too.

 

[Uncle99]

Are there instructions for calibrating the new heaters?

Apparently this heater has no calibration at all.
The instructions say no calibration required for this “smart Advanced” heater, dual temp sensors always right to +- 1 degree.
Too bad, very well made and sealed fully submersible heater, but rendered useless with accurate water temp
Put them on my InkBird controller, it will at least, make them useable.

I should have made a better choice.

 

[edd59]

how do you know your glass thermometer is accurate?
can we buy known accurate thermometer, i used a glass thermometer, heater, cheap digital and a school science class digital, all differant.

 

[EeyoreIsMySpiritAnimal]

how do you know your glass thermometer is accurate?
can we buy known accurate thermometer, i used a glass thermometer, heater, cheap digital and a school science class digital, all differant.

You can calibrate with ice water. (With boiling water too but the temps we run are closer to 32F than 212F, so may as well calibrate to the closer one... less room to drift)

 

[Uncle99]

how do you know your glass thermometer is accurate?
can we buy known accurate thermometer, i used a glass thermometer, heater, cheap digital and a school science class digital, all differant.

I don’t know it’s accurate.
But combined with 3 digital thermometers, all within .2 degrees, and the four years running well in the DT, I just doubt the 81-82 degrees can be accurate.
Actual 81-82 degree water feels “warmer” by touch than my DT water.
Live and learn. They will work well with my Inkbird controller, so not to bad a lesson.
Any future heater/thermometer I buy will have the ability to calibrate.

 

[Uncle99]

Update (7 days later).

I’m wrong.

While there is no calibration on this heater, today, 7 days in the water, they both report water temp correctly.

I have touched nothing.

They take time to get a good read????

Seems to be the case here.