Most accurate will be number one. IR guns are good but have trouble with some surfaces like hammocks. They can also get confused on some materials due to issues with how it measures heat and how those surfaces store or emit heat, meaning the gun can read higher or lower than actual temps on certain materials. You can use the probe to get an accurate temp, then check it with the gun to see if it matches. If it does, you can use your gun for daily checks and just use the probe to check weekly or every other week or something to make sure your gun is still working correctly.
I also wish to confirm since the UVB should only span through 2/3 of the tank length from the hot side, does it mean the remaining 1/3 length which is also the cool side of the tank (no basking light) will be totally without any lighting and a bit dark?
I also wish to confirm since the UVB should only span through 2/3 of the tank length from the hot side, does it mean the remaining 1/3 length which is also the cool side of the tank (no basking light) will be totally without any lighting and a bit dark?
You can always put a LED household bulb on that cool side for lighting - I have a 120 gallon tank and have a 75 watt basking bulb in the middle of my tank that lights up the cool side - my UVB sits in the front middle of my tank w / that basking bulb behind the UVB --- UVB is in the tank and the basking bulb is on top of screen - those temps run in the 90's in the middle of my tank - you can also use a UVB that is 1/2 the length of the tank rather than 2/3 of the tank - it is up to you - I am using a 24" inch in my tanks