As a first time pond builder, I was satisfied with the project I completed except I don't know if I have a leak or evaporation. The pond is 13 X14 about 3.5 feet deep, 4 waterfalls with drops between 4 inches to 10 inches. The pump is a 4500 GPH and I have good flow with a couple of falls having rock underneath that causing nice ripples. Today, I lost about 1/4 inch of water with the temperature around 85 degrees. Since I live in a new development, I have no trees(shade). Do I need to worry?