Swim Pond Questions

If you’ve been dreaming of a swim pond but aren’t sure if you want to “jump in”, here are some answers to common questions about swim ponds.

Q: Do swim ponds have to be big? My yard is small.

A: No! Swim ponds can be quite small. In fact, Minnesota Waterscapes built a swim pond complete with stairs down into the water right next to a patio/entrance. The swim area is the size of a hot tub. (roughly 10ft x 12 ft x 2.5/3ft deep), just right to cool off on a hot summer day!

Q. Are Swim Ponds safe and clean?

A: Yes, beneficial bacteria, the invisible powerhouse reduces 99.9% of all harmful microorganisms with a properly sized filtration or wetland system for the swim pond. Additionally, beneficial bacteria don’t break down in sunlight like chlorine does. The bacteria live on rock surfaces and filter media. Adding more oxygen can boost bacteria and so does providing additional space for bacteria to colonize, like a wetland or rocks in the water. Wetlands slow the water flow down, allowing bacteria and rocks to filter the water.

Chlorine, on the other hand, will break down in sunlight so additives are sometimes added to the chlorine help slow the breakdown. Chlorine can kill up to 99.9% of harmful microorganisms but some like Cryptosporidium can last in chlorinated water up to 10 days before dying. (source: MayoClinic.org)

Running swim pond water through a wetland filter removes larger particles first like organics like leaves and pieces of poo. The beneficial bacteria which break down harmful organisms and chemicals such as ammonia and nitrates into harmless particle, live on the rocks in wetland filters.

Q. Can I swim with plants and fish?

A. Yes, if you want to swim with koi or goldfish, you certainly can. The beneficial bacteria breaks down fish waste and is fish safe, pet safe, and people safe. If you want plants like water lilies or fish but want to protect them, your swim pond can also be built with a separate area for fish and plants. The water circulates through both areas, giving your swim pond the boost of plant filtration.

Q: How much maintenance does a swim pond require?

A: If the filtration is sized properly, maintenance should be roughly 1-2 hours per month.

If you live near trees that drop leaves in Autumn, your maintenance will be slightly higher but a wetland filter does a slick job collecting leaves in one spot, making removal much easier. Again, it depends on the proper sizing of the filter/wetland.

Q: How much does a Swim Pond Cost?

A: A small swim pond with natural stone walls and steps (10 ft x 15′) costs about $28,000. A large swim pond (30ft x 60ft plus intake bay and beach) costs about $145,000. These are 2025 prices from the Minneapolis/St. Paul area in Minnesota. Variables to the cost would be the type of stone used, the depth (going deeper costs more and may require fencing or permits depending on city ordinances), and ease of access to machinery needed for construction.