Fish's new tank project

[Fish]

Yesterday I stopped by Gold's and picked up a Stealth heater and a thermometer.






So far I am very impressed with the stealth - it has held the temp rock solid compared to my second hand ebo (which had water drops inside the glass!) - as an added bonus, it matches the red/black color scheme I have going on.
I have one question though. This morning I found that the part of the heater that gets hot was covered with little bubbles, I blew them off but there appears to be a film or scale left on the outside. I could probably scratch it off or use some vinegar to scrub it but I am worried that it will just build up again. Is this a problem? Any thoughts?


One final piece of equipment:





This is my laboratory grade digital metering pump that is going to add topoff water at the exact rate of evaporation.

Cheers,

- Chad