Aquarium Glass Thermometers - why such a temp range

[bigbird]

Hello All,

This is very frustrating. Why is it, that all Aquarium glass thermometers are from 0-50 C, if in tropical conditions, we need water temp from 20 to approx 35 C. This 0-50 scale, makes the coloured tropical area so small and minute to ready, that you need a magnifying glass to find out the temp of the tank.
Does anybody know of a manufacturer that makes glass thermometers for Aquariums from a range 20-35 C in large numbers ?
uff glad got this off my chest, made me mad these useless ones on the market. cheers jk :thumbup:

 

[Stan]

I've aked this question to myself for years too, JK. The only one Ive found is one made by Resun that is 10*-40* but it is one of those spring ones with the dial and it's out by a few degrees either way. Perhaps you have a good marketing idea?:dk:

 

[Brengun]

Yup all of us over 40 whose eyesight isnt quite what it used to be is in the same boat.
Drives me crazy trying to read the little tiny reading. Best ones I got have a green area colored as safe zone for tropicals. Hey at least if its in the green thats ok even if the range is about 24C to 30C.

 

[zeebo]

Yup all of us over 40 whose eyesight isnt quite what it used to be is in the same boat.
Drives me crazy trying to read the little tiny reading. Best ones I got have a green area colored as safe zone for tropicals. Hey at least if its in the green thats ok even if the range is about 24C to 30C.

yep, Bren, I use the same ,with the green zone in white plastic protector. Picked them up after dropping the larger all glass one in the tank:wb: so i replaced them all . Very good imo.

Georgie

 

[kl3ggy]

This maybe a stupid question and I'm prepared for the answer that will come, but why not use the $8 battery digital ones?

 

[dw1305]

Hi all,
Digital thermometers are usually more accurate, but you often get failure of the LCD displays on cheap ones, whereas a good glass one lasts forever.

You can get much more accurate thermometers that are designed for clinical or lab use, they will be more expensive and you will need to find your own way of mounting them in the aquarium. (you can just use a drilled wine cork, you need a bigger cork than you think you are going to need).

Because of the expansion is much greater in spirit thermometers than in mercury thermometers, and "total immersion" thermometers are generally more accurate than "partial immersion = 76mm" ones, you want an accurate reading you need a BS1704 standard "300mm mercury filled thermometer with yellow background".

Some manufacturers have stopped using mercury and use "Ertco blue fluid", which is meant to be much better than the red spirit and almost as good as mercury, these will run from about £15 up to the hundreds. <http://http://www.coleparmer.co.uk/catalog/product_view.asp?sku=9390900>.

The less accurate (but still pretty good) standard thermometers sell for about £2 each. I just use one of these with a "safety suspension ring", so you can tie some cotton thread onto it and fish the thermometer out without putting your hands in the tank. This sort of thing.

<http://www.newtonresources.co.uk/secondary/education/3,5,8/1681/305mm_Total_Immersion_Mercury_Laboratory_Thermometer.htm>

cheers Darrel

 

[Brengun]

I found the digital ones that actually go inside a tank last for the batterylife of maybe 6mths to a year and by the time you go to change the battery, water has gotten inside and corroded it.

The ones that sit outside and just have a meter that you put in the tank can be out by as much as 1.5C. I tested a couple of those and one was out by that much. I have since permanent markered the discrepancy on the front so it is usuable, just add 1.5C to its reading.

You can pay a lot of money and get a really good one like the temperature alert ones with an alarm for temp fluctuations but when you have multiple tanks like me you can really only affort to add them to a couple of tanks with the more expensive fish in them.

 

[MiT]

I just use the cheap digital ones that are on ebay and cost incl delivery around $2AUD each.

I put one on the outside at each end of my 4ft tanks and find that they are about 0.5C different end to end.

If they play up i just chuck em in bin and grab another (buy 5-10 at a time) but they do seem to last at least 12 months. Its prolly cheaper to just buy another than change the batteries when they go flat. (at $2 or less each new) :lol:

Pete

 

[jessonthenet]

Try one of these:

http://www.ebay.co.uk/itm/EASY-READ-AQUARIUM-THERMOMETER-/330640522160?pt=UK_Pet_Supplies_Fish&hash=item4cfbb5fbb0#ht_766wt_932

 

[bigbird]

thanks Jess we have these as well. I was just wondering why they vary from such a large scale from 0C to 50 C and the temp we are interested in is between 20-36C. The green area thus becomes very hard to read. cheers jk :thumbup:

 

[jessonthenet]

temp range

Maybe write to the companies who make them and see what they have to say. Usually if I have a query regarding a product I email the maker directly. API sent me a response when I had a question about something and so do most companies.

Might be a scientific reason why the scale has to be like that. Not that sure how a thermometer works. With mercury all I knew was something to do with heat making molecules bounce around more causing pressure and then moving the mercury up the thermometer but long time ago I learned that. Might not even be correct.

I have one of those thermometers I put a link about, sure it only cost me a quid though and I couldn't verify its accuracy. Plecs do knock them off the glass like most stick on glass thermometers.

 

[bigbird]

ok will try. i am also sure there is a reason. cheers jk :thumbup:

 

[jessonthenet]

I can't see any reason apart from it looks right as the correct temperature range sits bang in the middle of 0 and 50 degrees C so maybe just an aesthetic thing.

If you have trouble reading the thermometer you could always use one of these:

 

[bigbird]

:lol: wow would need hell of a large tank though :woohoo:

 

[jessonthenet]

good enough excuse as any, " I need a tank to fit my thermometer" same as people buying large fish for small tanks knowing fine well they will be 2ft each in next few months and the wife wont be able to say no to a bigger tank down the line. Then may have to knock through into the kitchen.

 

[bigbird]

love it, am just building a new rack, thanks to my missus. cant wait and will post pics later. cheers and happy new year jk :thumbup: