Which thermometer is correct.

[Hemmdog]

Temp has very little effect. Now a daily swing of 10 degrees may cause some stress but softies and lps are quite hardy so even then they may not have any issues.

I disagree. Temp being rock solid is one of the most important parameters. If your temp is changing it’s also changing your available oxygen, which changes pH, which effects corals ability to calcify, numerous other negative effects as well. Stability is key is reefs, having stable temp helps keep everything else in line and not fluctuating.

I went from running my 90 with heaters with internal temp control, thought my coral was doing well. I was wrong, after upgrading my heating to a ranco temp controller and titanium heaters without internal temp control, my coral took off, much better pe, more growth. My whole reef is much more stable in general (minus the power outage I had last week). My temp doesn’t fluctuate at all now. 78 rock solid 24/7. Where as before I went up or down 2 degrees around 78. So I’d say it definitely matters and have first hand proof in the pudding.

 

[tehmadreefer]

What glass thermometer should I use? Any decent under 20? My fiance is watching my spending Haha I've spent 30$ this week testing cheapo thermometers to see which brand is best for the price

Just look on Amazon or Ebay for some with good reviews. Also you should "calibrate" a new glass thermometer by doing the ice water test first. Some aquarium oned have a green part that shows the good range to be in and they are quite cheap.

 

[tehmadreefer]

I disagree. Temp being rock solid is one of the most important parameters. If your temp is changing it’s also changing your available oxygen, which changes pH, which effects corals ability to calcify, numerous other negative effects as well. Stability is key is reefs, having stable temp helps keep everything else in line and not fluctuating.

I went from running my 90 with heaters with internal temp control, thought my coral was doing well. I was wrong, after upgrading my heating to a ranco temp controller and titanium heaters without internal temp control, my coral took off, much better pe, more growth. My whole reef is much more stable in general (minus the power outage I had last week). My temp doesn’t fluctuate at all now. 78 rock solid 24/7. Where as before I went up or down 2 degrees around 78. So I’d say it definitely matters and have first hand proof in the pudding.

So the temp in the ocean doesnt fluctuate? Sorry, you can disagree until your blue in the face, but it really isnt a concern just as ph doesnt really matter much and why the hits unthe hobby a long time rocking sps tanks dont even test ph.

https://www.reef2reef.com/ams/tank-parameters-of-some-masters.263/

 

[Peter Clark]

I never fully trust these types of thermometers. First time I was in the hobby 10 years ago I had a 29g reef that used a digital thermometer that looked identical to your Top Fin one. I know that type is branded many different things, and I believe mine at the time was a Coralife. I didn't bother checking the temp often, but one day noticed it was rather low. Not really thinking about it I assumed it was a heater problem so slightly turned them up. Well lets just say I managed to see the effects of global warming first hand. I even managed to kill GSP! I then realized what happened and got a glass thermometer. For my new build I do have one of the cheap temp probes in addition to an Apex temp probe, but I still have glass as a backup to keep an eye on it.

Long story short, what may be more accurate today may be less accurate tomorrow. Glass is always a good backup to compare to.

 

[Peter Clark]

Or be anti technology like me and use this. It does temp and salinity and never needs calibration.

Ah I miss those old glass hydrometers. That is what I used when I was a kid and had a tank just for marine hermit crabs. And I spent far too much time looking for one of those when I had tanks back in college, although I think I mainly used a swing arm style then. The glass type worked beautifully. I'm always tempted to go back to one, but I figure I'll stick with a refractometer since that is what all the cool kids use these days.

 

[Hemmdog]

So the temp in the ocean doesnt fluctuate? Sorry, you can disagree until your blue in the face, but it really isnt a concern just as ph doesnt really matter much and why the hits unthe hobby a long time rocking sps tanks dont even test ph.

https://www.reef2reef.com/ams/tank-parameters-of-some-masters.263/

The surface temp fluctuates but more than 30 meters down not much. Not 4 degrees up and down a day. I don’t test pH but big pH swing does negatively impact coral. It’s proven coral calcifies best at 8.17 pH so I hope for that when I do test it quarterly. It’s been 8.2 every time I’ve tested.

 

[mfinn]

I've found those little cheap thermometers can be off as much as 1-1/2 to 2 degrees when compared to each other.
I've bought 3 at a time and had each show a different temp.
Even Lifeguard Big Time and Temp thermometers can show a difference of a degree between 2 bought at the same time.

The only thermometer that I found that is consistent is the Hanna Checktemp.
I have 2 that show exactly the same temp down to .1

 

[Reefnoobz90]

Hanna makes 2 of them, the 98501 and 98509

https://clearchoiceaquatics.com/col...roducts/hi98501-checktemp-digital-thermometer

 

[mfinn]

I like the Hanna HI98509

 

[427HISS]

If any of you know about,...5-10 thermometer companys, make a vote thread. That would be very interesting. I'm always thinking about accuracy, quality and longevity. Temp is one of the top points in a healthy tank. If someone will take-up the research, please have at least those three points.

 

[shred5]

I have 2 thermometers and is marina and the other brand is topfin they are 1° appart from one another. I have a third brand coming in the mail to be the tie breaker but which of these brands would you trust more?

I had a bunch of the ones on the right when I used to breed clowns and they are horrible. Some of them were 4 or more degrees apart from each other.
They also start to have issues allot. I was being cheap since I had allot of tanks. Stay far away.

Get a nist calibrated thermometer, I think BRS sells one. Use these to test other thermometers or calibrate them.

 

[bigcheese]

I have 2 thermometers and is marina and the other brand is topfin...

That exact thermometer on the right is sold under at least 5 different brand names. I've had a few, they don't last long before they drift.
I found their accuracy was entirely dependent on the battery voltage. The included battery supplier suffers from some qc issues, and I've gotten new-in-box ones that read as much as 3* low. I even had one last year that had a mercuric oxide battery in place of the regular alkaline.
You might want to repeat the test with a brand-new, name-brand battery like energizer or duracell.

Now... I can't imagine the Marina is going to be radically different internally. Hagen is a pretty good company by my estimation, but it's still the same chinese silicon powering it. I'd hazard a guess Hagen goes the extra step to use a reputable battery supplier, but I don't have one, so I can't confirm.

 

[427HISS]

Doesn't someone,....make a accurate one that ain't a piece of crap !?

 

[bigcheese]

Doesn't someone,....make a accurate one that ain't a piece of crap !?

Sure... the old-school glass ones that are based on 500-year old technology... [emoji6]

Seriously tho.. The cheapie electronic ones are relatively precise, mostly stable... even if not *accurate* out of the box. I've gotten used to pulling them out of the package, putting in a new battery, then checking against a known-good reference (in my case a glass lab-grade homebrewing thermometer I've had for 20+ years). Then apply "Kentucky Windage" to figure the offset and put a label on the case so I remeber to add a half degree or whatever.
Rinse and repeat every six months when the battery needs changing or thrown out if I see any internal corrosion. 999 out of 1000 times that's within a decimal place of my Apex thermometer.

 

[mfinn]

Doesn't someone,....make a accurate one that ain't a piece of crap !?

Hanna

 

[vetteguy53081]

I do NOT trust the little black one. If any, I prefer the intank glass unit physically in water. I have a JW with magnet mount which is always a match with titanium readout on my Finnex heater

 

[ca1ore]

Does it really matter. Hobby grade thermometers like those are usually only accurate to plus/minus a degree. More important that they’re predictable/precise. Just pick one ..... then it’s ‘right’.

 

[Paul Sands]

Put the probes in ice with a little water. Whichever reads 32 degrees wins.

 

[rob G]

I bought an extra Thermopop from Thermoworks last time they went on sale and use it to compare to my controllers numbers just to be safe. I trust it above most other options within a reasonable price point.

 

[rob G]

I bought an extra Thermopop from Thermoworks last time they went on sale and use it to compare to my controllers numbers just to be safe. I trust it above most other options within a reasonable price point.

 

[rob G]

I bought an extra Thermopop from Thermoworks last time they went on sale and use it to compare to my controllers numbers just to be safe. I trust it above most other options within a reasonable price point.

 

[radiata]

I'd trust the one that has NIST certification, which I doubt either has. If you really want to know the temperature, use one with NIST certification, like:
https://www.bulkreefsupply.com/hi98509-checktemp-1-digital-thermometer-hanna-instruments.html
Otherwise, you're just another a fish out of water.