An accurate, precise thermometer without spending a fortune??

[Fish Fan]

Hey guys!

I fully expect to get blasted just for asking, but I would like to hear recommendations on a dependable thermometer without having to spend big-bucks on a lab-grade thermometer, which I fully understand is the best option.

I'm trying to determine what temperature my heaters are running, regardless of their set point, or what the little five dollar digital thermometer reports.

Right now I'm testing with a thermometer that I use for cooking, which had great reviews for that purpose:



When I test my two newly cycling tanks, the temp fluctuates by as much as a degree or more, and that's going back and forth from tank to tank, to tank to tank, with this thermometer bouncing around. A degree or so is not a big deal when you're cooking a steak, but......

Can anyone recommend a thermometer that doesn't cost a fortune, but would be useful for dialing in the temperature of my tanks?

Thanks very much!

 

[Cichlid Dad]

Penn-Plax Stainless Steel Thermometer https://a.co/d/2YH0hZA


Go with an old school analog . Set tank to 78. If the thermometer is off 1 deg it's fine. Stability is the most important thing.

 

[EeyoreIsMySpiritAnimal]

Hey guys!

I fully expect to get blasted just for asking, but I would like to hear recommendations on a dependable thermometer without having to spend big-bucks on a lab-grade thermometer, which I fully understand is the best option.

I'm trying to determine what temperature my heaters are running, regardless of their set point, or what the little five dollar digital thermometer reports.

Right now I'm testing with a thermometer that I use for cooking, which had great reviews for that purpose:



When I test my two newly cycling tanks, the temp fluctuates by as much as a degree or more, and that's going back and forth from tank to tank, to tank to tank, with this thermometer bouncing around. A degree or so is not a big deal when you're cooking a steak, but......

Can anyone recommend a thermometer that doesn't cost a fortune, but would be useful for dialing in the temperature of my tanks?

Thanks very much!

1 or 2 degrees over the course of the day is fine.

Old fashioned mercury thermometers are probably the most reliable, but there are good inexpensive scientific digital thermometers available like this one:

 

[TokenReefer]

A degree or so is not a big deal when you're cooking a steak, but......

But what? A degree or two?!

 

[EeyoreIsMySpiritAnimal]

But what? A degree or two?!

Three

 

[TokenReefer]

Three

Sorry I had tenths in my head for whatever reason... Yeah ng.. Goin to bed

 

[KStatefan]

I use a NIST calibrated Thermopen One. They run them on sale a lot especially if you do not care about color.

 

[hoffmeyerz]

I use a digital candy thermometer to verify tank tamp and when mixing salt. Temp is very important for certain candy stages so they tend to be very accurate. I just happened to have it already so it became my go to temp checker.

 

[gbroadbridge]

Hey guys!

I fully expect to get blasted just for asking, but I would like to hear recommendations on a dependable thermometer without having to spend big-bucks on a lab-grade thermometer, which I fully understand is the best option.

I'm trying to determine what temperature my heaters are running, regardless of their set point, or what the little five dollar digital thermometer reports.

Right now I'm testing with a thermometer that I use for cooking, which had great reviews for that purpose:



When I test my two newly cycling tanks, the temp fluctuates by as much as a degree or more, and that's going back and forth from tank to tank, to tank to tank, with this thermometer bouncing around. A degree or so is not a big deal when you're cooking a steak, but......

Can anyone recommend a thermometer that doesn't cost a fortune, but would be useful for dialing in the temperature of my tanks?

Thanks very much!

You don't need a precision thermometer to run a reef tank.

You simply need a reliable thermometer with repeatable results and use it to maintain a temperature within 5 degrees or so.

 

[EricR]

I agree that a degree or two off is no big deal but it would be nice to have an accurate measurement anyway.

For calibrating my inkbird, I just use 3 cheapie digitals that I've accumulated along with a cooking digital similar to what you have in post #1. (The cheapie digitals span a little less than 1 degree usually and the cooking thermometer is somewhere in the middle so I just go by that)

Most budget hobby thermometers seem to claim +/- 1 degree accuracy and Hanna sells a digital that claims +/- 0.5 degree accuracy for around $50 but I've never bought or used that one.

 

[Fish Fan]

Hey guys! Thank you for all the help and replies!

I want to be clear, my temp is not off a degree or two throughout the day (well, it probably is, but…).

What I’m saying is i have two tanks running right now. I can place my kitchen thermometer in one tank and it will read say 84.2 F (I am fish-less cycling at higher temp). Then, I put the thermometer in the second tank and take a reading. After that, I put the thermometer immediately back into the first tank, and it will read like 82.8 F. So where am I, 82 or 84? And if the thermometer is off by a degree or two, that spread could be more like 81-85. This is my concern.

I have a candy thermometer, so that may be an option. I will also check out some of the options you guys linked above.

Thanks again for the help and suggestions!

 

[EricR]

I'll just say that my digital cooking thermometer doesn't seem to have as much variance as yours as I've done similar multiple times -- check DT, check other water at different temperature, check DT again pretty quickly.
*mine has always come back the same or within 0.1-0.2 degrees the handful of times of done it,,, could've just been luck but I don't think so

 

[BeanAnimal]

I use a NIST calibrated Thermopen One. They run them on sale a lot especially if you do not care about color.

I used to be a big thermapen fan... I own many and have gifted many more. Not so much anymore for the price.

I have a pile of different thermos, and the thermapens are actually pretty slow and no more accurate they anything else... NIST or not. So I don't dislike them, just don't feel $20 vs $120 makes them any better than many other knock-offs or competitors.

 

[Fish Fan]

I'll just say that my digital cooking thermometer doesn't seem to have as much variance as yours as I've done similar multiple times -- check DT, check other water at different temperature, check DT again pretty quickly.
*mine has always come back the same or within 0.1-0.2 degrees the handful of times of done it,,, could've just been luck but I don't think so

Interesting. I really like my kitchen thermometer for cooking, I love how it's got a magnet and lives on my fridge, right at hand. But maybe you have an even better thermometer than I do? Or maybe the battery in mine is dying? Either way, I think I need one in the kitchen and one for my tanks, so I'm looking to pick up something else.

I saw this thermometer, seems to have really good reviews compared to others:


EDIT: After reading more about that thermometer I learned that it cannot be user calibrated, and so there are better choice, I believe.

I used to be a big thermapen fan... I own many and have gifted many more. Not so much anymore for the price.

I have a pile of different thermos, and the thermapens are actually pretty slow and no more accurate they anything else... NIST or not. So I don't dislike them, just don't feel $20 vs $120 makes them any better than many other knock-offs or competitors.

Good to know! I'm not looking to spend a fortune here, just trying to find a reasonably dependable thermometer I can use to double check my tank temps. Thanks, Bean!

 

[Fish Fan]

OK, after sniffing around a bit tonight, I ordered this thermometer. It had good reviews, it was priced at $10 with a 50% off coupon, so why not. It can also be calibrated, is supposed to be +/- 1 degree F, it's waterproof, and includes a bottle opener to boot. If it doesn't work well for my aquaria, it can be my meat thermometer that lives permanently on our camper.



At 5 bucks I certainly don't expect lab-grade data collection, but if it's more repeatable than what I have now I'll be happy.

I'm still open to options in the sub $100, ideally sub $50 range for a thermometer.

Thanks everyeone!

 

[EricR]

OK, after sniffing around a bit tonight, I ordered this thermometer. It had good reviews, it was priced at $10 with a 50% off coupon, so why not. It can also be calibrated, is supposed to be +/- 1 degree F, it's waterproof, and includes a bottle opener to boot. If it doesn't work well for my aquaria, it can be my meat thermometer that lives permanently on our camper.



At 5 bucks I certainly don't expect lab-grade data collection, but if it's more repeatable than what I have now I'll be happy.

I'm still open to options in the sub $100, ideally sub $50 range for a thermometer.

Thanks everyeone!

Woh,,, $5 -- bought one just for fun since it was so cheap. Thanks for the tip.
Hanna CheckTemp line claims +/- 0.5 degree accuracy and runs $40-$50 from what I've seen -- looks like they have a couple of different formats.
*I'd be tempted to go that route if I really cared enough any more

 

[Fish Fan]

Woh,,, $5 -- bought one just for fun since it was so cheap. Thanks for the tip.
Hanna CheckTemp line claims +/- 0.5 degree accuracy and runs $40-$50 from what I've seen -- looks like they have a couple of different formats.
*I'd be tempted to go that route if I really cared enough any more

LOL! Glad to help, and I'm chuckling at your "if I really cared enough"

For five bucks, I'll give this a shot. What do I have to lose, except for five bucks.

EDIT: I didn't know about the Hanna CheckTemps. I will look into those for sure; thank you!

 

[Fish Fan]

OK, officially intrigued by the Hanna CheckTemp's! This is basically what I was thinking when I posted this.

Which model is better, do you think?

https://www.bulkreefsupply.com/hi98...D=7216&indexName=brs_prod_m2_default_products

Or this one, which is water resistant and smaller?



Thanks guys!

 

[EricR]

I have no experience with these just remember seeing some years ago that Hanna had +/- 0.5 degree accuracy (claimed) models.
*one shopping note, the $59 one in the Amazon link looks to be the same model as what SaltWaterAquarium website has for $41 and assume their shipping price is reasonable based on past experience

I kind of get the feeling that the Hanna models' main difference is just the format -- meaning do you want a single hand-held almost pen-like format or do you prefer the larger one where you can stand up (or hold) the unit and dip in a separate probe.

 

[FrugalReefer]

I find the analog thermometers that you can get at Petco or PetSmart to be very reliable.