Used gray shower water passes through a series of filters sand activated carbon and microfiber and then through ultraviolet light uv sterilization before returning still hot back to the showerhead.
How to make a recycle water out door shower.
Insert a pvc right angle joint into the hole with transition and pvc cement and glue the ball gag with transition cement.
You can also recycle gray water which is the drainage from your sinks showers laundry dishwasher and other non toilet sources.
Capturing this water may take a little more effort but the benefit to the environment and your wallet can make gray water recycling well worth it.
A simple method for reusing shower water with a 5 gallon bucket is to collect the water that runs from the shower while it is heating up for use in toilet flushing or plant watering see reference.
Glue the pvc collar to the abs with abs pvc cement.
Run the irrigation hose from the tap to the lid of the barrel.