14 replies to this topic

[Cicolid]

Which brand & type of thermometers do members use ?

I have 4 AquaOne digital ones. After an outbreak of "white spot" I decided to test them as the water felt cold to the touch but I was getting a reading of 26.1C in my Malawi tank.

After replacing all batteries, I placed all 4 in a 60x24x18 planted tank, all the sensors were within a 5cm radius of each other.
The readings varied from 18.6 to 24.5 C.

I had to email AquaOne twice before I got a response.

It will be interesting to see their reply.

Col

[Cawdor]

Which brand & type of thermometers do members use ?

I find the most accurate thermometers I use are the cheapo small glass ones, $1.95 from AoA. I have one digital one, the Marine Minder or something. It's off between 0.5 and 1 degree C. I put three glass thermometers into the same tank as well as the digital one, I got the exact same reading from all glass ones and the digital was about 0.8 lower than it should be.
So once you figure out what it *should* display instead of what it does display, it's handy because it shows up to .1 accuracy. Too bad there's no option to calibrate. Maybe the more expensive digital ones have it, but for my purposes I'm gonna just get the cheapo ones, they do the job rather well. After all, all I need to know is if the temp is 26 or not

[dazzabozza]

Hi Col

I'm using 6 of these units across my different tanks - http://www.jaycar.co...w.asp?ID=QM7209

I just ran around and tested the temps using a traditional thermometer and the reading's were within 0.5 degrees of the electronic temp which I'm happy with. By far the best feature is the alarm. I had a marine tank bomb out of me after doing quite a large water change and the heater dying in the process, wasn't till a couple of days later that I realised. Also with all the high temps over Xmas I had losses also. With these units I set alarm warnings between 22deg (Minimum temp) and 30deg (Maximum temp). Anything outside this range will signal the alarm.

Pro's

- Hi and Low Temp alarms.
- Max and Min temp memory (keeps track of the what temps are reached until such a time that u clear the memory).
- Extremely cost effective compared to some aquarium brands.
- Uses a AAA battery compared to the dearer watch style batteries found in other units.
- Has 2 sensors (one built into the unit which gives the room temp, the other is a water proof probe on the end of a 1 metre wire).
- Has built in magnetic holders else comes with optional velcro and double-sided tape.

Con's

- A slight difference in temp readings between the room temp sensor and water probe sensor (even when sharing the same air space)
- Has fridge / freezer written on it LOL!
- Jaycar never have enough stock on hand to get a good multiple buy price. If this is the case pay for all of them and wait for the rest to arrive in their next order.



Dazza

[Mr_docfish]

With the units with the cables as pictured on the fridge freezer ones, it is advisable to not immerse the cable, just the sealed rubber/silicone end piece. Moisture can get into the cable otherwise and affect the reading. This of course takes time to occur, but in essence it should be avoided if you want an accurate reading. (the temp will show higher than the water is in this case, as the cable corrodes, and resistance is increased, and the reading will change with the increased resistance.)
Some of the one piece submersible units, (not sure which Col has got), do have a problem if any moisture gets in, which for units that are submersible, it is almost a guaranty that it will.

[dazzabozza]

.... it is advisable to not immerse the cable, just the sealed rubber/silicone end piece....... as the cable corrodes, and resistance is increased, and the reading will change with the increased resistance.....

Cheers for that Oliver. Is something I'll definately keep in mind. It's a shame the water levels change continously else u'd be able to permanently mount the probes in a fixed position to try and prevent the corrosion. At this price I'd be happy to replace my units every couple of years if need be.

Dazza

[sydad]

.

Con's

- A slight difference in temp readings between the room temp sensor and water probe sensor (even when sharing the same air space)

Dazza

Hi Dazza,

The noted difference between room temp. and water temp. is not a fault with the thermometer, but is rather a simple physical fact that is almost
always evident when dealing with an unsealed water source in a room containing (relatively) dry air.

Cheers, Syd.

[Leevers]

I tend to steer clear of these electronic units. I have had the same problem with numourous brands and have given up. As stated above, i find the best thermometers are the glass tube type as they provide an adequate reading for the application and their fail safe.

[Barramundi]

I use the AquaOne ones with the lead to the sensor, but also have a glass one in each tank too as back up. I also have found the Digital ones out between .5 & 1 degree. But for
"at a glance" checking as I go back & forth past the tanks it's near enough.
I check the glass ones at feeding times as they're a little tricky to read... old eyes & also cos the suction cups are pretty crap & so the therm floats around the tank all the time. But hey, guess can't have everything, at least they are accurate.

[Sazabi]

You sure it's not the other way around the digital is accurate and the mercury ones out by 0.5 to 1C?

[Wet Dreams]

I've got one of the digital thermometers and a few times ive questioned its readings..dont trust it at all. so im now looking out for more reliable and accurate units.

[dazzabozza]

By far the best feature is the alarm. With these units I set alarm warnings between 22deg (Minimum temp) and 30deg (Maximum temp). Anything outside this range will signal the alarm.

Another great save when I got home tonight. An alarm was sounding in the fish room and I found a tank sitting at 32 degrees (instead of 25!). Thermostat on the heater had stuck on and came good after a few shakes.


Daz

[fourdapostle]

throw it out daz if it jammed once it likely will again, just like all the digital thermos. I had a few but they were all showing diferent temps in the same tank, couldn't trust them at all, back to the tried and true glass ones....

[dazzabozza]

Hey Dave

U may have misread the above The digi thermometer is what saved the fish. The heater's (standard glass) thermostat had jammed on constantly heating the water.

A glass thermometer wouldn't have sounded an alarm. I'll be sticking with the digi's


Daz

[Warby]

hrmmm i think i will pick up one of those fridge/freezer thermometers next time i go past jaycar.. cheers for the tip daz

[Melvin]

Bit of a bump of an old thread, but goes to show how well the search function works.

I was up for a couple of new thermometers, one for my new tank and one to replace the 'aqua one' one on my old tank which I thought was playing up. I went down to Jaycars and picked up two of the fridge/freezers ones. I then place FIVE thermometers into my old tank and came up with the following data;

Aqua one - 24.5c
Glass thermometer - 27c (A little hard to read)
Fridge/freezer #1 - 27.2c
Fridge/freezer #2 - 27.2c
Meat thermometer - 27.3c

Those fridge/freezer ones are sensational! Quite accurate and have the alarm function, as well as the min/max to check the fluctuation over the day. And just an added bonus of room temperature display also. BIG thanks to Dazza for the heads up!

Regards Melvin