Thanks all for the cooling info. So far just opening the top of the enclosure as it's on hinges and completely flips up. But obviously not a long term solution especially when raining or snowing (that's a nasty word)!!! Will do some research into my best setup and look at some examples. So far this is my schedule: 15 min, 30 min, 1 hr, 1 1/2 hr. As per Ted not going to double down every day with the age of my pond. Probably here on out add 1 hr per day until shutting down the deep diffuser for winter.