So guys i took some readings today. A surface temp of 64, was very windy today .water temp of spring water entering pond 54. Water temp where kids were catching perch and trout I'n 8 fow was 54. Temp at defuser on bottom (not running) was 50... The 18 ft hole was 46......... So you guys think Iam ok running defuser 4 hours a night I'n the 10 ft range ?
