Before you recycle spa water for any purposes you should check the local ordinances and laws in your area. Hot tub water is considered gray water and in some areas of the country there are restrictions about recycling gray water. If you do not live in a restricted area, your hot tub water can be recycled after waiting at least 3 days after you last added chemicals. Also be aware that
Some hot tub models can use salt water systems that may damage lawns or shrubs, so it’s not recommended for use on plants.