Which thermometer to trust???

lazydaze73 · 02/05/2015, 01:01 PM

So which thermometer do i trust. I have 3 ways to measure.
1) Digital cooking thermometer
2)Lifeguard Little time and temp thermometer in my sump
3)Heater themselves.

Im assuming the heaters themselves are the least accurate. I have them both set at 77, which is pretty close to what the lifeguard one i have in the sump. But the digital cooking thermometer i have says 81. Doesn't fluctuate, stays exactly 81, the other one moves up and down a little bit pretty frequently. I assumed the cooking thermometer would be the most accurate, so is that what i should base my tank temp on?

IMG_0576.jpg

Mark9 · 02/05/2015, 01:03 PM

I'd take an average of all 3.
The thermometers we buy are +-2 degrees accuracy.

ReefsandGeeks · 02/05/2015, 01:26 PM

I'd say calibrate them yourself and see which one is the most accurate, then go with that one. You can do this by bringing some water to a rolling boil, like practicaly spashing out of the pan. put your thermometers in there and see if they read 212F (assuming they go that high). Then take a glass of cold water and add tons of ice. stir the icewater for a couple minutes to make sre it is well mixed and put your thermometers in there. should read 32F. I know These temps aren't close to where you are actualy reading, but if it's accurate at both temps it is likely to be just as accurate at your tanks temp.

If you can't calibrate them yourself I'd probably put my trust in the lifeguard. a cooking thermometer isn't likely to be made to the accuracy you'd like in your tank. The thermometer in the heater itself would be my second choice after verifying that it is close to what your lifeguard thermometer reads.

TruReef · 02/05/2015, 01:29 PM

Easier yet, fill a glass ice, then half fill that glass with water so there is more ice than water. Stir for a bit and put in thermometer, ice water is 32 degrees....
http://www.foodrepublic.com/2011/04/...od-thermometer

ReefsandGeeks · 02/05/2015, 01:30 PM

I have an infared laser thermometer I use which is very high quality and calibrated (I use this for many other things as well), and also have one of those color changing strips on the side of my tank. You'd be suprised how accurate and consistant the color changing strip is. Plus you can get one at petsmart for like $2 I think.

cloak · 02/05/2015, 01:33 PM

Those little stickers you place on the side of the tank have never steered me wrong. (ball park figure)

FWIW, I've had my hands in tropical tanks for a LONG time. A thermometer is not really needed anymore. You can just tell by putting your finger in the water sometimes.

FraggledRock · 02/05/2015, 02:28 PM

yea i use multiple sources for any parameter i need to check

snorvich · 02/05/2015, 02:37 PM

Quote:

Originally Posted by cloak

Those little stickers you place on the side of the tank have never steered me wrong. (ball park figure)

FWIW, I've had my hands in tropical tanks for a LONG time. A thermometer is not really needed anymore. You can just tell by putting your finger in the water sometimes.

Same here. I can feel it immediately. On the other hand, I do have a calibrated thermometer (which is not cheap) if I really cared to know exactly. Which I don't.

fishchef · 02/05/2015, 02:39 PM

Temperature stability is important. Your heater or heaters should be on a controller. Most controllers have a temp. readout. Choose an appropriate temp for your stock and maintain it. We have a Pinpoint thermometer and our Ranco controller has a digital readout. They're close.

lazydaze73 · 02/05/2015, 09:38 PM

Thanks for the suggestions. I tried calibrating by boilng water and then freezing water. It read low on boiling by two degrees, and read high in freezing by 4 degrees. Think I'm gonna go with the temp gauge in my sump

running scott · 02/06/2015, 07:52 AM

I think as long as temp changes are gradual most of the animals we keep can adjust to the changes. Does anyone think the water temps on a reef don't change?

username in use · 02/06/2015, 07:56 AM

Quote:

Originally Posted by running scott

I think as long as temp changes are gradual most of the animals we keep can adjust to the changes. Does anyone think the water temps on a reef don't change?

How about water parameters during major rain storms with massive runoff from the surrounding land?

Breadman03 · 02/06/2015, 10:28 AM

A couple degrees don't really matter much in this hobby, unless you are really pushing the boundaries. I wouldn't bat an eye at any of those readings, though 81 is about as high as I would go.

ReefsandGeeks · 02/06/2015, 10:31 AM

I know that on the reefs there are rain storms, cloudy days, cold fronts...etc which do cause changes in light, salinity and water flow for all of the reef life and sometimes can be a reletivaly fast change. I don't think that means this is ideal though. I havnt gone diving on a reef to know, so I'm speculating here, but I can just see in my head that the coral woulnd't be very happy on those days. Survive? sure, they do. But as a hobbyist I'm sure most of us try to keep as many of our peramiters in precisely optimal conditions as often and as stable as possible to keep out marine friends ars happy as we know how. I think it's important to take the measurments to track what's been going on in your tank, but I also don't think you should stress about a gradual temp swing here and there or something like that.

As far as your calibration goes, it sounds like your thermometers are acceptably close to trust. Most of the time when you boil water at home it will read 1-2 degrees low because a typical stove top with a pan will not be able to keep the water at 212 throughout the water. Just not strong enough to perfectly overcome the heat loss to the surroundings. So that's normal. The ice bath is usualy more spot on, but if the ice wasn't aggitated well enough that could cause that. Good job on calibrating your oen equipment though. I calibrate everything I can calibrate at home every 3-6 months depending on how much I trust it. Other things I occasionaly bring to work and calibrate on my lunch break. (I work in a calibration laboratory and have access to some of the most accurate and precise instruments, so plenty of trust there). Not cheap to send your stuff out for calibration though.

Sk8r · 02/06/2015, 12:47 PM

Touching your tank glass as you pass is a good habit.
I use two, a Coralife digital thermometer, which is inexpensive and usually very accurate, and a stick-on, down at sand level, just as a doublecheck. You only have a 5 degree window between optimum and dangerous (ideal is about 79/80) so you cannot afford a mistake. The very LAST thing to trust is your heater setting: the number of tanks that have gotten into trouble with a malfunctioning, shorting, or outright WRONG heater is, well, a whole lot. The heater is the most unreliable and risky element in your tank, and you should buy the best, but never ever trust what it tells you.

Reef Frog · 02/06/2015, 01:28 PM

My home thermostat is very accurate. I've propped up aquarium & other thermometers right next to it to check its accuracy. The other suggestions here are good too.

DragRacinGramps · 02/06/2015, 01:30 PM

I'm with fishchef here and what he said in post#9, and also what Sk8r said. The heaters we use are the most unreliable poorly made pieces of equipment in our systems, and the one that if it fails or should I say when it fails can destroy your entire system especially if it fails in the on mode. For those reasons if you at all have the means GET a controller! The controllers have calibrated temp probes that are probably the most accurate of any device out there for a true temp reading. The controller can also be set up to shut the power off to the heater if a set temp is achieved mine is set to cut the power at 83. It can also set off an alarm and even call your phone with some controllers to let you know the heater has failed. I just recently acquired the Apex Jr and absolutely love this thing, and for the time being I am using it only to control the heater and run two dosing pumps.

Greg 45 · 02/06/2015, 01:40 PM

None of them a nist calibrated thermometer

igot2gats · 02/06/2015, 01:50 PM

One digital, and one non-digital; both in the sump. If one is way off, then you know it's time to check things out / get a new thermometer.

Goldndoodle · 02/06/2015, 02:52 PM

The cooking thermometer is probably not meant to be very accurate at low temps - probably meant to be more accurate in the 130 - 180 degree range for meats.

Have you considered a heater controller? Over the top would be an APEX that you could control a lot of things with. Or very cheap ($14 at Amazon) - STC-1000

Mishri · 02/06/2015, 03:01 PM

Quote:

Originally Posted by cloak

Those little stickers you place on the side of the tank have never steered me wrong. (ball park figure)

FWIW, I've had my hands in tropical tanks for a LONG time. A thermometer is not really needed anymore. You can just tell by putting your finger in the water sometimes.

haha that is true, I noticed my tank felt too warm and noticed my heater was on, i knew the heater was broken, didn't even need a thermometer

(used one anyway, 82 degrees, I keep my tanks at 76), I don't keep thermometers in my aquarium once things are up and running normally anymore. been keeping fish since '86.

Greg 45 · 02/06/2015, 03:27 PM

A broken clock is correct twice a day
maybe 6 thermometer's take average of 6 there is the answer

tkeracer619 · 02/06/2015, 05:17 PM

None of those...

Ranco temp control and a floating glass thermometer.

I go to a box store look at all the floaters and pic the ones in the middle of the variance.

The ranco self tests the probe and is a commercial heavy duty temp controller that a bunch of us use.

Set the heaters thermostat a few degrees above the ranco.

jason2459 · 02/06/2015, 07:48 PM

Yup, I don't trust any of them. Ranco for me as well to control my heaters. Its about the only thing I come close to trusting.

tkeracer619 · 02/06/2015, 07:55 PM

My reef controller cost me over a $1000. I use a $45 ranco etc for my heaters

and my controller to send me emails.

02/05/2015, 01:01 PM	#1
lazydaze73 Registered Member Join Date: Nov 2014 Location: Murrieta, ca Posts: 247	Which thermometer to trust??? So which thermometer do i trust. I have 3 ways to measure. 1) Digital cooking thermometer 2)Lifeguard Little time and temp thermometer in my sump 3)Heater themselves. Im assuming the heaters themselves are the least accurate. I have them both set at 77, which is pretty close to what the lifeguard one i have in the sump. But the digital cooking thermometer i have says 81. Doesn't fluctuate, stays exactly 81, the other one moves up and down a little bit pretty frequently. I assumed the cooking thermometer would be the most accurate, so is that what i should base my tank temp on? IMG_0576.jpg

02/05/2015, 01:29 PM	#4
TruReef Registered Member Join Date: Nov 2009 Location: Fruit Cove, FL Posts: 617	Easier yet, fill a glass ice, then half fill that glass with water so there is more ice than water. Stir for a bit and put in thermometer, ice water is 32 degrees.... http://www.foodrepublic.com/2011/04/...od-thermometer __________________ The Dude abides. I don't know about you but I take comfort in that. It's good knowin' he's out there. The Dude. Takin' 'er easy for all us sinners. Current Tank Info: AGA 180g mixed reef, 60" Sunpower 8 bulb, SRO-3000int

02/05/2015, 02:28 PM	#7
FraggledRock Registered Member Join Date: Dec 2014 Location: New York, New York Posts: 2,185	yea i use multiple sources for any parameter i need to check __________________ “For most of history, man has had to fight nature to survive; in this century he is beginning to realize that, in order to survive, he must protect it.”― Jacques-Yves Cousteau MarineBio.org Current Tank Info: 40 Gallon Breeder w/ Bean Animal Overflow 20G Sump, Mixed Reef.

02/06/2015, 12:47 PM	#15
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	Touching your tank glass as you pass is a good habit. I use two, a Coralife digital thermometer, which is inexpensive and usually very accurate, and a stick-on, down at sand level, just as a doublecheck. You only have a 5 degree window between optimum and dangerous (ideal is about 79/80) so you cannot afford a mistake. The very LAST thing to trust is your heater setting: the number of tanks that have gotten into trouble with a malfunctioning, shorting, or outright WRONG heater is, well, a whole lot. The heater is the most unreliable and risky element in your tank, and you should buy the best, but never ever trust what it tells you. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

02/06/2015, 01:30 PM	#17
DragRacinGramps Registered Member Join Date: Oct 2014 Location: S.E. MI Posts: 152	I'm with fishchef here and what he said in post#9, and also what Sk8r said. The heaters we use are the most unreliable poorly made pieces of equipment in our systems, and the one that if it fails or should I say when it fails can destroy your entire system especially if it fails in the on mode. For those reasons if you at all have the means GET a controller! The controllers have calibrated temp probes that are probably the most accurate of any device out there for a true temp reading. The controller can also be set up to shut the power off to the heater if a set temp is achieved mine is set to cut the power at 83. It can also set off an alarm and even call your phone with some controllers to let you know the heater has failed. I just recently acquired the Apex Jr and absolutely love this thing, and for the time being I am using it only to control the heater and run two dosing pumps. __________________ 75g mixed, t5 4 bulb,eshopps 100h,gfo/carbon reactors,UV, 2-3" bed 16 head frogspawn,12 head hammer,trumpet,brain LPS,orange mushroom,kenya tree,finger leather,spaghetti leather,zoos,gsp,toadstool. Current Tank Info: 70 Gallon Freshwater planted, and a 75 gallon sumpless mixed reef

02/05/2015, 01:03 PM	#2
Mark9 Registered Member Join Date: Aug 2013 Location: Atlanta Posts: 2,497	I'd take an average of all 3. The thermometers we buy are +-2 degrees accuracy.

02/05/2015, 01:26 PM	#3
ReefsandGeeks Registered Member Join Date: Sep 2014 Location: Pittsburgh, PA Posts: 1,708	I'd say calibrate them yourself and see which one is the most accurate, then go with that one. You can do this by bringing some water to a rolling boil, like practicaly spashing out of the pan. put your thermometers in there and see if they read 212F (assuming they go that high). Then take a glass of cold water and add tons of ice. stir the icewater for a couple minutes to make sre it is well mixed and put your thermometers in there. should read 32F. I know These temps aren't close to where you are actualy reading, but if it's accurate at both temps it is likely to be just as accurate at your tanks temp. If you can't calibrate them yourself I'd probably put my trust in the lifeguard. a cooking thermometer isn't likely to be made to the accuracy you'd like in your tank. The thermometer in the heater itself would be my second choice after verifying that it is close to what your lifeguard thermometer reads.

02/05/2015, 01:30 PM	#5
ReefsandGeeks Registered Member Join Date: Sep 2014 Location: Pittsburgh, PA Posts: 1,708	I have an infared laser thermometer I use which is very high quality and calibrated (I use this for many other things as well), and also have one of those color changing strips on the side of my tank. You'd be suprised how accurate and consistant the color changing strip is. Plus you can get one at petsmart for like $2 I think.

02/05/2015, 01:33 PM	#6
cloak Moved On Join Date: Jul 2000 Location: Stockton, CA Posts: 14,854	Those little stickers you place on the side of the tank have never steered me wrong. (ball park figure) FWIW, I've had my hands in tropical tanks for a LONG time. A thermometer is not really needed anymore. You can just tell by putting your finger in the water sometimes.

02/05/2015, 02:39 PM	#9
fishchef Registered Member Join Date: Feb 2009 Location: St. Louis, MO Posts: 1,222	Temperature stability is important. Your heater or heaters should be on a controller. Most controllers have a temp. readout. Choose an appropriate temp for your stock and maintain it. We have a Pinpoint thermometer and our Ranco controller has a digital readout. They're close.

02/05/2015, 09:38 PM	#10
lazydaze73 Registered Member Join Date: Nov 2014 Location: Murrieta, ca Posts: 247	Thanks for the suggestions. I tried calibrating by boilng water and then freezing water. It read low on boiling by two degrees, and read high in freezing by 4 degrees. Think I'm gonna go with the temp gauge in my sump

02/06/2015, 07:52 AM	#11
running scott Registered Member Join Date: Apr 2009 Location: Bradenton,Fl Posts: 219	I think as long as temp changes are gradual most of the animals we keep can adjust to the changes. Does anyone think the water temps on a reef don't change?

02/06/2015, 10:28 AM	#13
Breadman03 New Old School Join Date: Feb 2012 Location: Luzerne County, PA Posts: 3,293	A couple degrees don't really matter much in this hobby, unless you are really pushing the boundaries. I wouldn't bat an eye at any of those readings, though 81 is about as high as I would go.

02/06/2015, 10:31 AM	#14
ReefsandGeeks Registered Member Join Date: Sep 2014 Location: Pittsburgh, PA Posts: 1,708	I know that on the reefs there are rain storms, cloudy days, cold fronts...etc which do cause changes in light, salinity and water flow for all of the reef life and sometimes can be a reletivaly fast change. I don't think that means this is ideal though. I havnt gone diving on a reef to know, so I'm speculating here, but I can just see in my head that the coral woulnd't be very happy on those days. Survive? sure, they do. But as a hobbyist I'm sure most of us try to keep as many of our peramiters in precisely optimal conditions as often and as stable as possible to keep out marine friends ars happy as we know how. I think it's important to take the measurments to track what's been going on in your tank, but I also don't think you should stress about a gradual temp swing here and there or something like that. As far as your calibration goes, it sounds like your thermometers are acceptably close to trust. Most of the time when you boil water at home it will read 1-2 degrees low because a typical stove top with a pan will not be able to keep the water at 212 throughout the water. Just not strong enough to perfectly overcome the heat loss to the surroundings. So that's normal. The ice bath is usualy more spot on, but if the ice wasn't aggitated well enough that could cause that. Good job on calibrating your oen equipment though. I calibrate everything I can calibrate at home every 3-6 months depending on how much I trust it. Other things I occasionaly bring to work and calibrate on my lunch break. (I work in a calibration laboratory and have access to some of the most accurate and precise instruments, so plenty of trust there). Not cheap to send your stuff out for calibration though.

02/06/2015, 01:28 PM	#16
Reef Frog Registered Member Join Date: Feb 2013 Location: Maryland Posts: 3,121	My home thermostat is very accurate. I've propped up aquarium & other thermometers right next to it to check its accuracy. The other suggestions here are good too.

02/06/2015, 01:40 PM	#18
Greg 45 Registered Member Join Date: Aug 2005 Location: Bayonne,N.J. Posts: 1,159	None of them a nist calibrated thermometer

02/06/2015, 01:50 PM	#19
igot2gats Deeeetroit Basketball! Join Date: Dec 2008 Location: Grand Rapids, MI Posts: 1,063	One digital, and one non-digital; both in the sump. If one is way off, then you know it's time to check things out / get a new thermometer. __________________ Jeff Stop being lazy, and use the search function. Seriously. Current Tank Info: 75g DT / 20g sump / 20g QT - Eheim 1250, Tunze Osmolator 3155, GHL Profilux 3, 2 Tunze 6095, Tunze Wavebox, Aqua Illumination Hydra LEDs

02/06/2015, 02:52 PM	#20
Goldndoodle Registered Member Join Date: Dec 2013 Location: Monroe MI Posts: 576	The cooking thermometer is probably not meant to be very accurate at low temps - probably meant to be more accurate in the 130 - 180 degree range for meats. Have you considered a heater controller? Over the top would be an APEX that you could control a lot of things with. Or very cheap ($14 at Amazon) - STC-1000 __________________ I don't want an "instant reef" ... I want a successful reef! 120G DT: dual Jebao WP25s, (3) 48" BML LED fixtures, APEX controller 50G sump: Jebao DC9000, Finnex 300 heaters, SCA Skimmer, fuge Last edited by Goldndoodle; 02/06/2015 at 03:25 PM.

02/06/2015, 03:27 PM	#22
Greg 45 Registered Member Join Date: Aug 2005 Location: Bayonne,N.J. Posts: 1,159	A broken clock is correct twice a day maybe 6 thermometer's take average of 6 there is the answer

02/06/2015, 05:17 PM	#23
tkeracer619 Registered Member Join Date: Jan 2006 Location: Westminster, CO Posts: 17,289	None of those... Ranco temp control and a floating glass thermometer. I go to a box store look at all the floaters and pic the ones in the middle of the variance. The ranco self tests the probe and is a commercial heavy duty temp controller that a bunch of us use. Set the heaters thermostat a few degrees above the ranco. __________________ Hobby Experience: 9200ish gallons, 26 skimmers, and a handful of Kent Scrapers. Current Tank: Vortech Powered 600G SPS Tank w/ 100gal frag tank & 100g Sump. RK2-RK10 Skimmer. ReefAngel. Radium 20k.

02/06/2015, 07:48 PM	#24
jason2459 Registered Member Join Date: Jul 2009 Location: Iowa Posts: 9,671	Yup, I don't trust any of them. Ranco for me as well to control my heaters. Its about the only thing I come close to trusting. __________________ rebuild and recovery log: No more red house, you'll have to click on my name and visit my homepage! You can check out my parameters at reeftronics dot net website and look for my username. Current Tank Info: 180g mixed reef w/ a beananimal overflow to a dolomite RRUGF. \| 20g long G. Smithii Mantis Tank

02/06/2015, 07:55 PM	#25
tkeracer619 Registered Member Join Date: Jan 2006 Location: Westminster, CO Posts: 17,289	My reef controller cost me over a $1000. I use a $45 ranco etc for my heaters and my controller to send me emails. __________________ Hobby Experience: 9200ish gallons, 26 skimmers, and a handful of Kent Scrapers. Current Tank: Vortech Powered 600G SPS Tank w/ 100gal frag tank & 100g Sump. RK2-RK10 Skimmer. ReefAngel. Radium 20k.