[Frogger]

I have been using floating glass thermometers to manage my reef tank temperature for as long as I have been keeping fish. I thought I was keeping my tank in and around 80 degrees F. Some times the tanks temperature gets as high as 82 and as low as 79. Two weeks ago I checked the temperature with my digital TDS metre and it read 86 degrees. At the same time my glass thermometer had crept up to 82 degrees. They are inherently difficult to read.

That got me really worried. I checked on the internet and the most precise reasonably priced thermometer is the 12" Vee Gee digital thermometer.
I purchased one off of Amazon.

The temperature in my tank was over 84 degrees when my glass thermometer was reading 80. This means that the temperature in my tank was closer to 86 when I thought it was 82.

Now that I know I have been boiling my inhabitants some of my problems I have had in the recent past have become clearer. High temperature equals lack of O2 especially at night when there is no photosynthesis taking place and everything alive is respiring (even most bacteria).

This is a similar problem I had with a bad batch of salinity calibration solution. You really can't trust any one source of information. If you are trusting your Neptune, your thermometer or any other one device if that device is out of wack you will have problems.

I have now lowered the temperature in my tank to 78 degrees and have a temperature controller managing the temperature. I will regularly check the temperature with my Vee Gee to make sure nothing gets out of line