Review on Enhanced Fluidmaster 8100 Flush 'n Sparkle Automatic Toilet Bowl Cleaning System with Blue Cartridge by Patrick Hamman

Not stable. Sometimes yes (you can see the blue in the water) and sometimes nothing. I bought two, one for each bathroom. So I spent a lot of time switching them back and forth and changing filters since a bathroom works better (both toilets are the same). But what works better is used less often. The other is annoying, inconsistent. I cut big holes in the cartridges hoping for better flow. Didn't bring anything good. One day I called the company and asked them about the discrepancy and was told that sometimes you couldn't tell because the cartridge was made differently. For real. That's a stupid answer. I went back to the blue pills.