I contacted Keeton Pond in CO re. heaters and learned that the titanium heaters Sean has are no longer on the market. The only ones available now are the inline heaters. Kirk recommended 1 KW per gallon. These heaters come in 1,500, 6,000, 11,000, & 18,000 KW sizes. Our 5500 gallon pond would use the 6,000 KW heater, which costs $849.00. That also means an increased electric bill in the winter of from $50.00-$400.00 at .10 per KWH because that particular heater runs at 6 KW per Hour, or .60 per hour.
Would love to know if anyone has any differing info.
Casey