[krackersmom2]

Can you use magnets in a crab tank? I wouldn't have anything metal to stick a magnetic gauge to in my crabitat....my tanks all have plastic edging around them (unless there is a magnet on the opposite side of the glass too). I prefer to use the gauges that have the temp and humidity on the same gauge. I bought mine for about $9.99 at Petsmart and it seems pretty reliable so far. Mine has the little colored zones .....specially designed for hermit crabs..... with one peek i can look to see if the needle is in the optimal color zone....it has numbers, but the colors saves having to squint to see them. It is also great for younger kids who cannot read temperatures yet, so it's a teaching tool too. They know if it's in the blue zone (too cold), yellow (just right), red( too warm).
I'm sure any temp. and humidity gauges are fine, as long as you know what the proper temps. and humidity should be. I'm sure we each have our own favorite brands too.