04-27-2010, 12:06 AM
| || | Heating aquariums - thermostat settings and temperature
I've ended up with three small (20L) betta tanks added to my fish menagerie. It's autumn and starting to get cool at night so I've been studying the temperature settings to ensure that everybody's warm enough. I have 25W Aqua One heaters in the tanks. The box said that that size was suitable for up to 25 litres.
The actual temperature in the tanks seems to be significantly lower than the thermostat setting on the heaters. For example, the temperature was showing as around 23 degrees, so I turned up the heater to read 28. At a setting of 28, the real temperature is around 25 degrees. (I'm pretty sure the measured temperature is accurate. I've glass thermometers in the tanks, but I bought a digital thermometer that goes in the tank, and I've measured them with that as well and get an equivalent reading to the glass thermometers' readings.)
Is this to be expected? Does it mean the heaters are calibrated incorrectly, or (too?) small for the tanks? Is there any problem trusting the thermometers and having the setting on the heaters set higher? Also, do you have to fiddle with the heaters at the change of seasons or will they be stable once you find the right thermostat setting regardless of the external temperatures?
Thanks for any help.