Use a 5g bucket, fill it with water, F/W is fine, make a 1:10 solution of bleach water in the bucket. Put the pump in the bucket, run it until the UV
is full and begins to exit the return line, turn off the pump, use "something (pvc
slipcap maybe) to plug the return line. Allow the UV
to sit for 30 min. (with the pump in the bucket). Then empty the bucket and the UV
, you can allow to air dry, or simply rinse with F/W. There "should" be nothing to soak up the bleach, but it will dissipate within 24 hours anyway. If you need it for immediate use, simply rinse for a few minutes with F/W.