Why you should install one

It’s easy to assume a clean out isn’t necessary and only adds extra cost, but the bottom drain line in a koi pond carries a surprising amount of debris. The spot where a pipe reduces from one size to another is the most common place for that debris to get hung up, and if it does, you’ll want a cleanout there so you can clear the line quickly instead of tearing anything apart. In every koi pond, the three‑inch bottom drain line eventually reduces to two inches to connect to the filtration system, and that transition point is exactly where a clean out becomes essential.

Pro Tip

The best approach is to place clean outs above ground near the filtration system, tucked somewhere out of sight but easy to access. Each bottom drain line should have its own cleanout installed before any size reductions or manifolds, ideally in a horizontal orientation. It’s a small detail in the build, but it can save you from major headaches down the road and keep your pond running smoothly.