cormer.27 Welcome, I live in the Phoenix area and have a 1000 gal system with a 500 watt heater. Which will keep my fish at or above 55 degrees when the weather gets down to 29 degrees.

I'm border line on the size of the heater, I do have another 500 watt heater for a back up or if the weather gets colder. If you check out my system, "Pipe Siphon by Apollo" you'll see that it is mostly buried in the ground. To help with the heat loss on cold nights I have a spar cover & a tarp to cover the fish tank. I also change my fill & drain growth bed into a constant flow during the night, this helps a lot.

Hope this helps...good luck, Apollo

I HAVE NOT FAILED. I'VE JUST FOUND 10,000 WAYS THAT WON'T WORK. Thomas A Edison