Hi yes it was, it will be a year in March. However annother window cleanner has been using one 4yrs, we both had to change our mebraines every 2yrs 40x40. He has got 4 years pluss with out any drop in water qaulity. as I'm now running 2 40x21 membraines they are about £170 plus vat each, so my first membraines again needed changing at 2yrs, so hence, try the uv light if I can get 4yrs that will be a masive saving. I will know in another 12 months.