Summer is a great time to purchase a pond thermometer to monitor the changes in your pond's water temperature. As air temperatures rise, the water temperature of the pond increases as well. The hotter it gets, the less oxygen is available in the water, making it difficult for fish to breathe. Higher water temperatures also raise the metabolic rate of fish and filter bacteria. Therefore, the hotter the water gets, the more oxygen the fish need.
Many pondkeepers like to add features to their ponds that are visually appealing, such as waterfalls, air pumps (also known as bubblers), or decorative statuaries (also known as "spitters") that shoot a stream of water back into the pond. These multi-dimensional elements add much more to a pond than a calming affect. Fountains, waterfalls and statuaries provide necessary aeration which oxygenates the water, helping to keep fish healthy.