What is the real temperature in my tank?

[99sf]

I have my 29 gallon tank set up with a 10 gallon sump. My Coralife digital timer reads 76 degrees--the probe is about 6 inches below the surface. My Stealth heater is set for 80 degrees. The adhesive strip thermometer is on the bottom corner of the tank and reads between 80 & 82. Which source do you think is most accurate?

[Shells]

Hi Christina,

From my experience I would not trust that coralife digital - I bought 3 of these and all of them were NOT accurate. All 3 read cooler than actual.

Shells

[Matt M]

I agree coralife does not make quality products

[Therapy]

I use a digital thermometer. One in the display tank via remote and one in the sump. I also have the temperature displayed on my chiller. All three have a different temperature by 2-3 degrees. Finding a accurate way to monitor my temperature has been difficult.

[99sf]

Sounds like I should get a different digital thermometer. I wish that there was an accurate cost-effective way to measure water temperature!

[DaveMorris]

I would be remiss if I didn't try to sell you on the benefits of a Reefkeeper controller.

Keep in mind that it is more important to have a stable temp as opposed to a particular temp. Yes, your tank needs to be somewhere between say...75 and 83 or so, but where in the range isn't really important. Find a thermometer that you trust to be true and just pay attention to temp swings. Most high grade food thermometers are accurate to within +/- 1 degree. That is plenty accurate for our tanks.

BTW, you can get a Reefkeeper Lite for $149 that will keep extremely accurate temp readings and can even help you control it. SDMAS will have one in the raffle at the July BBQ/Frag swap.

[99sf]

Dave, you have gotten me seriously interested in the Reefkeeper Lite One. It would be reassuring to know that the chiller & heater & lights are accurately controlled. When I recently had my manual timer for the light installed sideways on the powerstrip, the light period was erratic (it would get stuck on unexpectedly). Hmm... saving up for the Reefkeeper $149 option. Anyone here have experience with the base model Reefkeeper? I have seen a lot of posts about the Elite.

[DaveMorris]

I have one of the RKL units that I use for beta testing. Let me know if you want to check it out. I work weird hours but I am sure we can find a time that you could stop by and get a feel for it.

[Shells]

Dave,

Christina is up in San Fran now. You'll have to stop by her place next time you are up there for her to check it out

[Techknowledgy]

The Coralife thermometers are junk. I too have had three. All showed different temps. Strips are a waste of time and money. I use a meat thermometer from Kitchens and Things. (Or BB and Beyond... forget which.) It cost me 5 bucks and is quite accurate.

[99sf]

Thank you all for the feedback. I'm embarrassed that I have been relying on the Coralife digital thermometer. Dave, I'm going to be in S.D. from June 13-14. I'd love to stop by and see your controller & beautiful tank if you are in town that weekend.

[SDguy]

Just calibrate whatever you use against a real thermometer, like Roland suggested. IME whatever offset is needed remains constant.

[Bogg]

+1 peter, just use an old school thermometer to calibrate everything from.

[99sf]

OK, I took Roland's & Peter's advice and purchased a $10 food thermometer rated by the NSF. The Coralife was 6 degrees too low! Unbelievable.

[mikeyfromsd]

If you want to test how accurate your Coralife is, dunk it into some ice water. I did that with mine, found out that it was about 4 degrees off. They are junk.