I have decided to opt for tropical fish, rather than marine - for those of you who've read my earlier questions. So i fitted the heater kit.. what came with the BiOrb 30. And it has a little red light glowing to say that it's on, and a temperature dial at the top. I have set the temp to 24 (as instructed) but I cannot see any temperature gage on the actual heater, or in the box. So, how I am supposed to know when the water has reached 24 degrees? Please help meee. I dont know if there even was supposed to be a temp gage in the box, or on the heater. I'm just wondering and if there is, WHERE?!