I have a hydor got it a few weeks ago, never used it. Just got a new female and am putting her in a 1g until the 10g finishes cycling. My question is it says its okay under gravel, but I still worry lol maybe I am worrying to much but is it safe to put decorations and stuff on top? Is there a thing like to much gravel? The tank is acrylic or plastic...its one of those corner ones. anyways I just don't want any fire hazards. Would a glass bowl be better for this heater?