I have a visitherm 300 watt in my 125 gal. I noticed it has water on the inside so i need to replace it. What should i use? I have two rays in there and the old one has a guard on it, but i can't get the temp past 80. Do i need more watts or a better type of heater? keep in mind i have to have some kind of guard on it for the rays and I only have emperror 400s on the tank. I would like to get the temp higher and i would like it to be protected. Thanks in advance for the help!!!