In general, the natural swim ponds require at least 1x the area of the pond as a “wetland”, full of plants and a few feet of gravel. Water is slowly pumped through it to utilize the surface area of the gravel for hosting bacteria that do the cleaning, and the roots of the plants that uptake the surplus nutrients.
I wish I could do this, as one of my pastimes is gardening. But my hillside pond and distance to power make it prohibitively expensive.
The other aspect is you will lose a lot of water to evaporation in these systems. You will likely need to near constantly add water.
You may find that your pond is perfectly good for swimming without doing anything for the first few years until it hits a point at which the nutrient level supports unwanted plant growth. You can extend this time by not feeding fish, and making sure leaves stay out. Also do not fertilize lawns around the pond or allow farm runoff to enter. Also it can be lengthened by adding desirable plants like lilies, and in my case allowing cattails to grow where I normally have inflow to block leaves and sticks from getting in.
Another option is floating island planters. I forget who on this forum was doing it, but it is a clever way of pulling out excess nutrients.
B.cody note - Liquid is give very good advice - heed it.
Last edited by Bill Cody; 07/15/25 10:03 AM.
