heater

I've been noticing an interesting white matter that has been nestled in the bottom seams of my heater. Any idea what it is? It hasn't changed noticeably within the past week or so. I've attached a picture.

What brand & wattage of heater do you recommend for a 210 gallon tank? I know the general wattage/gallon rule, but am just curious if there are some lemons I should stay away from. I read some reviews on the Finnex 800 watt heater on BRS and there is some concern regarding some relatively...

So I've recently purchased two heaters: one a 300 watt Hydor, the other a 250 watt Marine land Stealth Pro for my 62 gallon set up. And I seem to have really bad luck. The first would heat the tank to over 80 degrees even when it was dialed all the way back to 70. Thinking the thermostat was...