Here's what I do with my SSK4. I have a separate bottle for used bleach. I don't top off the main bottle, and I save the used bleach in the second bottle. When main bottle is empty and the used bottle is full, I add bleach regenerator, aerate it all, and then that becomes that main bottle. I would recommend using bleach starter especially for your first batch of new bleach. That's the only time I used it, after that I used bleach regenerator to regenerate the used bleach and use it another time. I have used regenerated bleach For multiple runs, I think I did about 400 or 500 rolls on one 5 L bottle, regenerating it about eight times. It was still going strong, but I'm dumped it anyway just to be safe. Plus I had plenty of new bleach anyway (I bought the huge quantity containers of it) so it didn't hurt toss some