I'd still be concerned with 2 fish and a nem in a 3 gallon tank. If you have a lot of rock for filtration, you have little swimming room and a lot less water. If you have minimal rock, you have little filtration for only three gallons of water. I have a pico, (5.5 ecopico) and I was concerned adding a single goby..You have your "finger on the pulse" of the tank, so if you think your good, I won't argue that, but you can see the dilemma here with someone I have to perceive as new (given post count is what I have to judge from) asking a semi basic question about temperature, and stating that the current temperature isn't within current recommended ranges. Goof luck with the tank, pico's can be a real challenge.