For some homeowners, the idea of adding koi or goldfish to their backyard pond is even more of a goal than swimming. It’s perfectly possible to add fish to a swimming pond, even if you don’t plan to add filters or water treatment equipment. However, you’ll need to adjust your plans for fish to compensate for the natural style of care you’re providing. You also need to take a little extra care when swimming to ensure the fish aren’t hurt or disturbed. For the simplest and lowest maintenance swimming pond, consider skipping the fish and sticking to plants only.
Extra Maintenance and Care
Introducing fish into your natural swimming pond will greatly increase the amount of maintenance you must complete each year. Fish require you to dredge the pond more often to maintain the appropriate depth and keep water quality high. You’ll also need to test the water regularly to ensure that pH and dissolved oxygen remains within the right parameters for your chosen species. If you choose a species like koi that is particularly sensitive, you may have to add filters and heaters to keep your fish happy year-round.
Low Stocking Rate
Don’t follow the highest possible stocking rates for the fish species you choose when calculating your pond’s volume. Swimming in the same water as the fish adds to the water quality load on the filtration bed full of plants. If you stock as many fish as possible, the water will become overwhelmed with ammonia and the oils released by your skin. The fish will become sluggish and unhealthy, eventually refusing to eat and slowly dying off. If you want your fish to thrive while still enjoying swimming without guilt, aim for half the maximum stocking rate, or less, to balance the needs of both the fish and your swimming habits.
Treatments and Withdrawal Periods
Fish regularly require some kind of medical treatment to address illnesses or parasites. You can’t swim in the pond during treatment or afterward while it’s still circulating in the water. Swimming in a pond that’s been treated with insecticides or anti-biotics could affect your health. Yet, refusing to use any treatments for your fish could result in their suffering from painful and irritating conditions. If you want to reliably use your pond all summer long without interruptions in enjoyment, leave the fish for another pond so you don’t have to worry about water treatments and withdrawal periods.
For the simplest and lowest maintenance swimming pond, avoid adding fish. You’ll still have plenty of life in your pond from insects, amphibians, and birds that move in as the plants grow and offer a wonderful habitat and food.