Digital Thermometer, Which One And Placement.

[jotto]

Am looking to buy a more accurate thermometer for our tank to make sure the heater is up to the task and working and to keep the fish more comfortable.
I want to get a digital thermometer and wondered what you all use and where in the tank you place it....my guess would be in the opposite corner to the heater but as Im unsure, thought it best to ask!
Cheers.

 

[Uriel]

I have a fish minder which is a thermometer and alarm for water changes/filter cleaning. You can also set it up to alarm if water gets above or below a temp you set. I also have 2 glass thermometers one at each end of my tank. The water temp in your tank should be pretty consistent across the tank as long as heater is placed in the flow from filter. Water conducts heat 40 times faster than air so hot spots are uncommon.

 

[Aqua Tom]

I have two spirit thermometers one each end of the front of my tank & a digital jobbie whos sensor is near the middle back of the tank. I actualy trust the spirit thermometers more than the digital one.

 

[Skins]

Like Tom i use the spirit thermometers on all my tanks, I just check temps in the morning and last thing at night, but then i do like the sound of Uriel's divice.

Skins.

 

[raptorrex]

I have two spirit thermometers one each end of the front of my tank & a digital jobbie whos sensor is near the middle back of the tank. I actualy trust the spirit thermometers more than the digital one.

no comparison! spirit every time. Digis look good, but often are not, even, remotely accurate.(even in comparison to spirit.) a "accurate" digi costs over £100. and , to remain so, needs an minimum of £35 for calibration. so how accurate will a £10 or £20 item be?
honestly, you are better spending the dough, on something else.

 

[waterdrop]

Agree with raptor - this gets discussed off and on over the years and most conclude that the need for calibration puts the digitals at a disadvantage. The cheapest spirit thermometers have the advantage that you can buy several and use them against each other to get a clue when one is not right.

~~waterdrop~~
ps. I do find it bothersome how cheap the suction cups can be on these things sometimes. Has anyone found that they can buy separate and better suction cups? Are these available online in the US?

 

[raptorrex]

Agree with raptor - this gets discussed off and on over the years and most conclude that the need for calibration puts the digitals at a disadvantage. The cheapest spirit thermometers have the advantage that you can buy several and use them against each other to get a clue when one is not right.

~~waterdrop~~
ps. I do find it bothersome how cheap the suction cups can be on these things sometimes. Has anyone found that they can buy separate and better suction cups? Are these available online in the US?

bin a problem for me too. in the end i got, any old suction cup (aquarium safe), and put a hole in it. i then cable tied the thermometer to the suction cup. it works a treat.

 

[Aqua Tom]

ps. I do find it bothersome how cheap the suction cups can be on these things sometimes. Has anyone found that they can buy separate and better suction cups? Are these available online in the US?

Here are some that i have found. They are in the uk & hong kong but i am sure there must be some in the us.

http/shop.ebay.co.uk/?_from=R40&_trksid=p5197.m570.l1313&_nkw=aquarium+suction+cups&_sacat=See-All-Categories

 

[raptorrex]

ps. I do find it bothersome how cheap the suction cups can be on these things sometimes. Has anyone found that they can buy separate and better suction cups? Are these available online in the US?

Here are some that i have found. They are in the uk & hong kong but i am sure there must be some in the us.

http/shop.ebay.co....-All-Categories

good find, but the ones that fit mine, cost the same as a new thermometer, for 2.

 

[Aqua Tom]

ps. I do find it bothersome how cheap the suction cups can be on these things sometimes. Has anyone found that they can buy separate and better suction cups? Are these available online in the US?

Here are some that i have found. They are in the uk & hong kong but i am sure there must be some in the us.

http/shop.ebay.co....-All-Categories

good find, but the ones that fit mine, cost the same as a new thermometer, for 2.

whoaaa thats bad

 

[Uriel]

I have to say that although i don't rely only on my digital thermometers. Both the fish minder and the digital thermometer on my eheim filter/heater are very accurate and results are indistiguishable from the spirit thermometers.

 

[BIG BAD BARRY]

Spirit/alcohol thermometers are accurate and appear to be the best indicator of temp in the tank.

As pointed by other folk, digital thermometers start costing a lot for accuracy. The general digital thermometers for aquariums have an accuracy of +/- 1 celcius.

The downside with glass is that it has to be viewed. At 5 celcius it will be accurate but your fish will probably be dead!
I have just got on of these off ebay Item number: 190412837761. My heater failed previously.
I now keep a glass thermometer in there and this digital one as you can set a temperature range outside of which it will set off an alarm (not loud but sufficient).
Accuracy wise it appears to be with in 1 celcius. Just set your temp range taking this into account.

 

[Uriel]

Yeah that was kinda my thinking I bought a Hagen Marina Aqua Minder which is thermometer with an alarm for water temp Hi and low. It also has a function in which you set the maintenance times for water changes and filter maintenance and system maintenance and these tick down. Like i said i wouldn;t rely only on these but i think it's a nice addition to my tank.

 

[raptorrex]

I have to say that although i don't rely only on my digital thermometers. Both the fish minder and the digital thermometer on my eheim filter/heater are very accurate and results are indistiguishable from the spirit thermometers.

you see my argument would be, why buy a digital unit, at all. even you find the results "indistinguishable". why spent £5-30 on a digital. when £1.99-2.99 would lead to the same readings? perhaps most of all, spirit don't need a battery. inevitably as a battery runs down, the reading will become less accurate. but the spirit just carries on. I've seen some digis, and heard some people, that claim this is not a problem, but i find that hard to believe. as the owner of, not one, but two £100 calibratable thermometers. one of the things that is stressed is the importance of, fresh, good quality batteries. its hard to fathom the circuitry, inside a £5-30 unit, would be more sophisticated.

 

[Uriel]

I have to say that although i don't rely only on my digital thermometers. Both the fish minder and the digital thermometer on my eheim filter/heater are very accurate and results are indistiguishable from the spirit thermometers.

you see my argument would be, why buy a digital unit, at all. even you find the results "indistinguishable". why spent £5-30 on a digital. when £1.99-2.99 would lead to the same readings? perhaps most of all, spirit don't need a battery. inevitably as a battery runs down, the reading will become less accurate. but the spirit just carries on. I've seen some digis, and heard some people, that claim this is not a problem, but i find that hard to believe. as the owner of, not one, but two £100 calibratable thermometers. one of the things that is stressed is the importance of, fresh, good quality batteries. its hard to fathom the circuitry, inside a £5-30 unit, would be more sophisticated.

As previously stated i like the fact that there's an alarm that will go off if the tank temperature strays above or below pre-set temperatures. Well worth £5-30 as an extra failsafe to protect my fish. I don't really see the relevance of your 2 £100 calibrated thermometers. Of course they would be more accurate. Of course they will be far more complex devices with added circuitry for calibration ect. But more complex things do tend to be more sensitive to swings in power ect and i assume from the fact that there so expensive they are required to be extremely accurate for whatever task you purchased them for. I don't keep any fish that a 1/2 degrees centrigrade error would kill, although as previously stated i have 3 thermometers in the tank so i have the 2 spirits as backup. On the other hand if one of my heaters locked either on or off this could easily kill my fish and having the added alarm is an extra comfort level for me.