Thermometers

[thekarens]

I need a suggestion for a thermometer that's easy to read and reliable. The glass one is hard on my eyes ;)

[Chad Hughes]

You can get digitals for about 6 bucks.

[rickztahone]

i wouldn't really rely on the digital. i have two and both are unreliable when compared to the cheap glass thermometers. my tank read 88 on the glass one and read 83.4 on the digital. needless to say i brought the temp down but both of them had off readings like that

[Chad Hughes]

I tend to validate their accuracy by how closely they match the settings on my heaters. If I set a known good heater to 86 and the thermometer reads 86 with the heater light off, then I am pretty sure that it's about 86 degrees. Now, if it reads 88 degrees and my heaters are on, I always double check with the good old glass standby.

[mmorris]

My heater settings aren't a good match with the temperature, and my thermometers always measure differently! Digitals are, IMO, so inaccurate as to be useless. I finally purchased a Hanna temp/ph probe. I paid over $80 for it. The ph reading isn't consistant, but the thermometer seems to be.

[Chad Hughes]

Wow! That's an expensive heater. I would probably just get a standard glass heater before I spent that much money. Maybe you need a new Ph probe for the other half?

If my heaters start to stray more than a couple of degrees I throw them out. They are no longer trustworthy IMO.

[mmorris]

I calibrated it, calibrated it again, sent it back, got another, same problem, talked to the company who walked me through the calibration so I knew I had calibrated correctly, sent it back, got another...The ph is supposed to be accurate to within .01 but it measures my water out of the tap at between the high 6's and 8.0! There is no pattern to it. The water company came to my house to test my water (free of charge!) and the ph out of my tap is what they said it would be - 7.2. The drops seem to measure that, so I use the probe for the temp. only. A rather expensive thermometer!

[Chad Hughes]

That is weird! I have no other words!

[alpine]

Here we go again...I like the Coralife digitals.
Roberto.

[Chad Hughes]

Here we go again...I like the Coralife digitals.
Roberto.

LOL! Me too.

[kaceyo]

Using either digitals or heater settings to gauge accuracy is worthless. I've had three digitals and all three, placed in the same tank, gave readings from 82F to 87.
Heater settings are notoriously inaccurate no matter which brand.
The only accurate thermometers are the type used for temp critical work, like lab thermometers. They are gauranteed accurate within certain parameters.

Kacey

[mikel]

One of the thing that I was ripped off for when I first got into discus was the "digital thermometer" by the FS near me in Framingham, Ma. I was new to discus, and the owner stated in effect that "if you are going to keep discus, you need a very accurate thermometer, and the best one is a digital one"...which by the way cost more than $15. I bought it, thinking that's what I needed...and for the first three months, I kept dialling up my two heaters in my main tank because the digital kept reading 79 F-81 F. It actually never got above 82 F ever on the digital meter. As it turn out, my tank was a full 10 degrees hotter that that crappy digital indicated. I only found this out when I bought a cheap $2 thermometer, and it told me that my water was actaully 91 F!!!! I then confirmed it with a digital cooking thermometer, and another regular thermometer that indeed it was at 91F!!!!. I then tested my crappy digital thermometer, and indeed, no matter how hot the water was, it could never go about 82 F. All this accuracy for $15!!!!

Save your money, get one of those floating ones for two buck. :angry:

[Chad Hughes]

Wow! You guys have really had some bad experiences with digitals. I just can't say that I've had the same experience, that's all. I do verify temps frm time to time, especially at water changes. I cannot report any faults more than 1/10th of a degree.

Best wishes!

[mmorris]

I had a half dozen Coralifes going at one point and the range was 5 degrees. That's much too much. They are easy to read though!

[Chad Hughes]

I had a half dozen Coralifes going at one point and the range was 5 degrees. That's much too much. They are easy to read though!

I agree, way too much!

[doc3toes]

http://cgi.ebay.ca/Submersible-Aquarium-Digital-Thermometer-Water-Celsius_W0QQitemZ300270877040QQcmdZViewItemQQptZLH _DefaultDomain_0?hash=item300270877040&_trksid=p3286.c0.m14&_trkparms=72%3A1215%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318

i ordered 10 of these and found them pretty good.

good: cheap. accurate. they were really accurate, all 10 read within 0.1C of each other, and were spot on with the 3 glass thermos i had lined up with them. bad: one/10 died after a month (maybe leaked?). they also adjust a bit slow. like 30sec before u see the temp change.

[seanyuki]

Hi Ian,

Thanks for sharing the info.

Cheers
Francis :)



http://cgi.ebay.ca/Submersible-Aquarium-Digital-Thermometer-Water-Celsius_W0QQitemZ300270877040QQcmdZViewItemQQptZLH _DefaultDomain_0?hash=item300270877040&_trksid=p3286.c0.m14&_trkparms=72%3A1215%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318

i ordered 10 of these and found them pretty good.

good: cheap. accurate. they were really accurate, all 10 read within 0.1C of each other, and were spot on with the 3 glass thermos i had lined up with them. bad: one/10 died after a month (maybe leaked?). they also adjust a bit slow. like 30sec before u see the temp change.

[Chad Hughes]

http://cgi.ebay.ca/Submersible-Aquarium-Digital-Thermometer-Water-Celsius_W0QQitemZ300270877040QQcmdZViewItemQQptZLH _DefaultDomain_0?hash=item300270877040&_trksid=p3286.c0.m14&_trkparms=72%3A1215%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318

i ordered 10 of these and found them pretty good.

good: cheap. accurate. they were really accurate, all 10 read within 0.1C of each other, and were spot on with the 3 glass thermos i had lined up with them. bad: one/10 died after a month (maybe leaked?). they also adjust a bit slow. like 30sec before u see the temp change.

I have to say that I have had similar experience with these. I wonder if it was a certain ot of the thermometers that just weren't good? Interesting!

[richmond5]

Remember those long ones we used to use in chem lab. in high or university. Those are pretty accurate and you can buy them used on ebay.

[keiffer123]

I've had the problem of inaccurace too. I have two glass and digital thermometer all had different readings. One glass therm. read 88, another 82, and the digital 86 so I've taken the average of all three

[rly]

Yep i have used coral life and tom digital with with bad results not at all easy for me to read little glass thermometers
ron

[Don Trinko]

I had 5 of the $6 digitals. Not very accurate to start and eventualy on three of them the temp reading dropped 5 degrees. I tryed batteries and that did not help. Trew 3 away and ussed the other 2 as backup on my water stgorage. Don T.

[Jhhnn]

Even though I've been away from the hobby for some years, I liked the liquid crystal thermos back then, and I've acquired more from Jehmco to use today.

The precision manufacturing makes them dead accurate. Heat is the active force, it's always trying to escape, to equalize into the environment. So with warm water tanks, they read the temp of the water behind the glass, glass being a lousy insulator. If they're off at all, they'll read a hair low, consistently. For anybody with doubts, submerse one in the water and compare the reading to the reading of one stuck to the glass...

They're also cheap, almost indestructible, and easy to read.

I bought one of Jemhco's floating pond thermos for my aging vat, just so I don't have to stand on my head to read the temp- big and easy to read. I'll check the calibration against the liquid crystals when the time comes...

[Al M.]

What ever you do don't buy the Corallife, I bought 12 all were in the garbage in less than a year....

[Emilio]

coralife's digital thermometer is way, way, way off reading. go with the old reliable glass thermometer.

[Rod]

I agree with most, cheap glass floating thermometers are the way to go. When i buy them i go to a lps with lots of them in stock and compare readings. You will see some variation from one to the next, so i choose one with an average reading. :)

[KDodds]

I agree with most, cheap glass floating thermometers are the way to go. When i buy them i go to a lps with lots of them in stock and compare readings. You will see some variation from one to the next, so i choose one with an average reading. :)

LOL, yup. How hard can it be to mass produce a thermometer that agrees with the next thermometer made and discard the "bad" ones (Q&A anyone?). IN that respect, the "store brand" thermometers are MUCH worse than, say, the Hagen thermometers. I've actually passed up batches of "store brand" thermometers when there have been a dozen or two on the rack and they've displayed 4 or 6 different temperatures. Which one or ones is/are correct? Impossible to say, really. Given the shoddy craftsmanship, it could very well be that the "odd man out", the ONE thermometer that doesn't agree with any of the others is actually the ONLY correct one. ;) I prefer to get "name brand" thermometers from my LFS or online specifically for this reason.

[kaceyo]

I do the same thing Rod does. Buy them only when there are alot on the rack and go through them to get the ones reading a good average of all the temp readings.

Kacey

[thekarens]

Back to the glass ones are almost impossible for me to read. Unless there's ones out there that I haven't found that are bigger with bigger lines and numbers.

[Don Trinko]

While I was in Alabama visiting my brother I picked up an infrared thermometer at Harbot Frieght. It was $20 and apears to be within a couple of degrees. I have the typical glass thermometers in all tanks (yes; hard to read) but I use the infrared to take a quick check of the tanks.
Hold it near the tank and press the button. It even holds the reading for several seconds after you let go of the button. Don T.

[Chad Hughes]

Don,

That sounds pretty good! Would you say it's relatively accurate? What type of thermometer do you compare it to? Can you calibrate it? Thanks for any info!

Best wishes!

[Don Trinko]

No calibration. It is within 2 degrees of thermomitor reading. You can get more accurate IR's but they are more expensive.
I do not use it as my primary measument of temp. I use it to "verify" that the heaters are working and the temp is reasonable. Don T.

[KDodds]

Back to the glass ones are almost impossible for me to read. Unless there's ones out there that I haven't found that are bigger with bigger lines and numbers.


Have you tried placing them at the front of the tank and using a magnifying glass?

[Scribbles]

I found a thermometer at a local lfs that is easy to read and seems to be pretty accurate. It is a glass thermometer in a white plastic "frame" for lack of a better word. The numbers are printed in black on the white background with a green strip in the target range. It sticks to the inside glass with a suction cup so you can read it from the outside without playing "find the bobbing thermometer". I think I paid 3 or 4 bucks for it but I can read it.

[KDodds]

If this is one of teh ones where the glass tube is secured independantly within the white plastic frame, I've had them slip up or down, providing inaccurate readings.

[Scribbles]

Good point. I think that I'll mark the frame where the top of the thermometer is so I can tell if it slips. Thanks.