Tank Temperature...

[Gruffle]

Does anyone know how accurate the stick on thermometers are?

I have my tank set at 26c, although I think my fish would be slightly more comfortable with it set a bit lower I have an open topped tank and set it little bit higher to offset the loss of heat in the winter, especially overnight, brrr its cold

the thermometor on the side says 22-23c in the day, which i'm not too worried about, my fish seem perfectly happy but i was wondering whether the discrepency is accurate or not, as presumably the external thermometer would take into account room temp?

 

[smegforbrains]

They are pretty innacurate TBH IME.


Your best bet is to try and pick up a stainless steel meat thermometer or an automotive multimeter with temperature probe. Either of these should be calibrated with an accuracy of +/- 0.5 degrees celcius to pass the relevant standards for general sale.

 

[raptorrex]

any thermometer is only as good as the calibration it was given. i have 2 £100+ electronic thermometers, and they need a £40+ calibration every year or so. and one is out by 1.1 degrees now!!!!!! stick on items are ok for rough indications, spirit are better but fragile, mine tends to be within 1 degree of the electronic measurement. Mercury would be the best bet for a cheap and accurate thermometer, but the safety angle makes it a none starter.

many many moons ago, my mum was a nurse. i still have here thermometer now. baring in mind you are comparing a digital read out to a basic analogue one, after 50 years its still as accurate as my Fluke or Test Point Industry electronic do- hikky. only thing is, you have to shake the thing like mad, to return the reading to 0 after use.

 

[Miss Wiggle]

wouldn't trust it as far as i could throw it!

get a £2 glass one that sits inside the tank, they are accurate enough and cheap enough to not really matter about calibration etc, just buy a new one!

 

[smegforbrains]

Test Point Industry electronic do- hikky.

I just love your technical terminology



I built my own control units to take the control away from the built in thermostats on the heaters.


I use West 6100+ process controllers with PT100 probes in stainless steel sheaths. I have relay control output configured to on/off control. The heaters are turned up to maximum as the stats are not being used. Setpoints can be changed at the push of a button and the PT100 probes are accurate to 0.5%

I only have two of these units set up at the moment but I am looking to build a master panel to house ten controllers (I am now up to 8 tanks at the moment).

 

[Corleone]

At least in the US, very, very few mercury thermometers are still sold for consumer use. Most have a non toxic oil in them now, and aren't much less accurate. They're cheap, reliable, reasonably accurate (usually), and most aquarium thermometers have a glass or plastic housing around the thermometer to protect it from breakage.

The liquid crystal external thermometers I've found to be a crapshoot, especially if the room is colder than the tank. Mine right now says 68F, when the water is about 75F.

 

[Rooster]

accuracy does NOT matter one jot ! Its consistancy thats the key... as long as it stays the same temp, give or take a degree... then you are fine.

On the topic of thermometers, I have an alchohol one from when I was a kid, a mercury one... a mechanical clock-face one, half a dozen electronic ones, and LCD stick on quid jobs...
THEY ALL READ DIFFERENTLY !
The most consistancy I see is amongst the cheapo LCD ones... so they get my vote !


I have an industrial electronic one left over from photography - which was calibrated to NASA standards... which I would imagine to be "right" but some of the electronic aquarium ones are as much as 10c out. (this is out of the box ! and despite replacements)
If they wasnt bought as gifts I would bin the lot...

 

[smegforbrains]

accuracy does NOT matter one jot ! Its consistancy thats the key... as long as it stays the same temp, give or take a degree... then you are fine.

Not quite so. You still need to know the error of the actual reading.

 

[Corleone]

accuracy does NOT matter one jot ! Its consistancy thats the key... as long as it stays the same temp, give or take a degree... then you are fine.

Not quite so. You still need to know the error of the actual reading.

Exactly. A consistent temperature of 86 is bad for most fish - at that temperature, my liquid crystal thermometer might actually get up to the mid 70's. Going by it, I could easily set up a tank, stock it with fish, and wonder why I have a tank full of poached gourami in the morning. A fluctuating temperature isn't a particularly bad thing (it induces spawning in a great many fish, in fact), but too hot or too cold both are.

If a thermometer is off by more than .1 degrees, it either wasn't calibrated to NASA standards, or isn't anymore and needs to be recalibrated. Most products that use the NASA name are junk, in fact, NASA's standards aren't generally open to the public, and devices capable of being calibrated to within their tolerances are prohibitively expensive.

However, anybody can SAY they're calibrated to NASA standards by making up their own standards and naming them NASA Standards (NASA isn't trademarked, and can't be trademarked by any private entity). Take the Space Pen for example - NASA never actually bought any of them aside the free samples they were sent when the product launched, and the ones NASA does have have never flown in space. However, the pen claims to be "NASA Quality" and "the first choice of astronauts." For thermometers, you're talking about fractions of a degree over a 600+ degree range. Most consumer thermometers of any type fail at one or both extreme and are rarely accurate over more than about a 100 degree range.

 

[raptorrex]

who ever did the calibration, even NASA, it will need recalibrated after twelve months or so. indeed the more accurate a unit, the more important calibration, and regularly at that. a 10 year old, £100, electronic thermometer will be no more accurate than a £2 unit bought today off the market. lol, as for not trusting a calibrated industrial thermometer? the would at least be accurate to .01 of a degree.(by law) so however untrustworthy they are, the readings they give would be correct.

thing is, to me, it's not important. providing the fish are within their comfort area, usually far wider than most think, and you keep it consistent. it makes, not one jot of difference. even the cheapest units sold are within a couple of degrees, close enough to get a tank to the mid seventys

 

[Rooster]

The point was they are ALL inacurate.... doesnt matter it was bang on a couple of years ago, near enough is near enough !

 

[smegforbrains]

The point was they are ALL inacurate.... doesnt matter it was bang on a couple of years ago, near enough is near enough !

I think you are missing the point bud



No matter what the reading is or how accurate/innacurate it is, if you don't know the actual error margin, any reading is next to useless.

 

[Rooster]

, any reading is next to useless.

EXACTLY !!!!! thats why a 99p LCD will "do"...

 

[smegforbrains]

, any reading is next to useless.

EXACTLY !!!!! thats why a 99p LCD will "do"...

You are still missing the point!


Go away and think about it.

 

[Rooster]

, any reading is next to useless.

EXACTLY !!!!! thats why a 99p LCD will "do"...

You are still missing the point!


Go away and think about it.

Dont think I am... educate me