Temp ? Probe location.

I have a question regarding temperature and more location of sensor. I previously had it in my sump, no reason just didnt want more wires in the tank. It stayed pretty consitant around 73-74. I decided to move it into the tank today and later was reading 83, I paniced, looked at it again and was at 75, then it was at 88 minutes later. Was a couple inches in the water. I moved it back to the sump and stablized at 74.3. Where is a good location? I figured in the sump its measuring just water temp, in the tank more enviroment temp due to the lights. Any input? Ive checked the heater and it doesnt appear to have turned on today and it usually only does at night.

 

Started the tank in August and didnt have a heater. I forget when but at night things wouldnt look so good. I ended up getting a anemone with a injured foot and each night it would look worse. I knew the water was getting cold but only had 2 of the stick on glass color changing ones. One of them seemed accurate but the other was about 20 degrees higher. I wanted a digital but couldnt find one so i got a liquid one and a heater. Was worried about cooking anything so i set it lower. The liquid thermo has always started around 76, had the green " safe" range and is always in the middle. Then I got a digital to compare and put it in the sump and the liquid in the DT. Would like to increase but there is a wide range of opionion on what temp to run.

 

I got the nem Nov 2. Nice green BTA. Was from petco and I didnt expect to see something like that there. So I got it but it was attached to a rock. The lady tried for a while to get it off and she finally got it. But stupid me didnt look at it just took it home. Went to put it in and noticed its foot looked odd. That was my 2nd nem and didnt know if it was just different or injured. After a few nights with no heater it looked not so good, got a heater and it improved. No bad signs up to this point, eats good, opens nice. I have read it can take months for them to die, its been 2 months so I sometimes wonder what the final outcome will be.


As for the heater I wasnt a fan of the adjustment dial, it was a simple turn style and no real way of telling where your at. Yesterday I looked at it and it was set between 72 and 76. So I guess that would put it around 74. I increased it a little and after the heater turned off it stablized around 75.X and the liquid thermo in the tank read the same.