well is gettin pretty cold in florida some nights (down to the 50s) an i need a couple good heaters i was think about 3 stealth 250 watt 2 in the 150 an 1 in the 75 or 2 of those azoo titanium 300 watts just need a little advice thanks
being that you are located in Florida, im not quite sure how cold it actually is. But in California the winter can be pretty cold too also 50's. Well to answer your questions i would use 3 250watt stealth is your 150 and 2 250watt stealths in the 75.
If it was 50° here today I'd go outside in shorts and a t-shirt!!
It doesn't matter what the outside temperature is just the temperature inside the house.
It was -13° F this morning here but it's still 70° F in my house.
Anyways to answer the question. It all depends on what your tank is constructed of and how high you want to raise your temperature above the room temperature.
Use this calculator as a guide and add a few watts for comfort.