I just had a pool built by Anthony & Sylvan (our Rep Ray Jackson) here in Austin. We had a pool and spa done that is roughly 16,000 gallons with a 400,000 BTU heater. I interviewed 4 different builders and felt that Anthony & Sylvan had the best design, experience and no complaints on the BBB. The pool came out great and the entire process was smooth. They did make a error with our diamond tiles (see my post entered 1/11/07 by Russ). Now Anthony & Slyvan wasn't the most expensive and they weren't the cheapest. I just wanted a great quality pool without the headaches. Now regarding the heater, the other night I heated the spa for the first time. The water was 52 degrees which took 1 hour and 30 minutes to get to 102 degrees. When I turned on the heater I checked the gas meter and it took 3 1/2 Therms to get to 102. We were in the spa for another hour which took a total of 5 1/2 therms. Our last gas bill the cost of a therm was running .94 cents and if you include the other fees and taxes it was around a $1.45 a therm. So I figured out that it will run me about 8 dollars to heat from the mid 50's to 102. Now we are in the cold months and as the water heats up during the spring of course it will heat up faster because the pool water temp will be higher while using less gas and gas tends to decrease in price as we get into spring and summer. I also have the option to heat the pool which I don't plan on doing because it will proably cost around $60 to get it to 78 degrees and not really sure what it would cost to keep in in the high 70's consistently. But I do have the option to heat the pool water up faster in the spring so we can start using it earlier in the spring. Now I don't think solar would work with our pool due to the trees around our house and how the sun hits our house. The only way we could do solar I think is put the panels on the front part of our house's roof because that is where the sun would hit it directly through out the day. Plus I don't think our HOA would allow this because it would be seen from the street. Good Luck!!!