Your fish might appear stressed out, gasping for air close to the water’s surface or especially close to a fountain or waterfall.
Warm water has a low capacity for holding oxygen, while cooler water can hold gigantic amounts of oxygen. Warm water and increased activity go hand and hand, and that increased activity means the fish require more oxygen when less oxygen is available, thus creating a vicious cycle. Stressed fish often begin to develop diseases, and soon enough you’ll have a domino effect.
Considering the fact that most pond owners stock their ponds with cold-water fish, warm water is a real no-no. If your pond is constantly at a warmer temperature, you may want to consider a tropical fish like the swordtail or tilapia.
Beating the Heat
There are some preventative measures you can take in order to keep your pond from becoming a warm, unhealthy mess. It all starts with a well-designed water feature. Depth, plant coverage, shade, and circulation should all be considered when building a pond. A minimum of a two-foot depth is suggested so the bottom can remain cooler, and you’ll also want to stock your pond with a lot of plants. A good rule of thumb with plant coverage is to fill 1/3 to 1/2 of the pond’s surface area.
Perhaps one of the most important parts of a pond design is circulation. If possible, you’ll want to place your biological filter and mechanical filter across the pond from each other, so that all areas of the pond are skimmed and the water circulated.
Waterfalls, streams, and even fountains play a huge part in the oxygenation of the water in your pond.
Check It Out
The bottom line is that you need to keep an eye on your pond and let your fish and plants do the talking. If you have a balanced ecosystem, you don’t need to be checking your pond out everyday, but you do need to check it out every once in a while to make sure your plant and fish friends are healthy.