Christy, I did the bleach test 2 years ago, it didn't break up at all. I could tell it wasn't a bacterial matrix holding it together, I could drop it and the slab wouldn't break
I have to scrap the inside of my sump walls, and even the PVC parts of my zeo reactor were completely white. Pretty sure this has something to do with the growth problem, just not sure what...
I used kalk for a while last year, then stopped and put my Ca reactor back online, no change. Not even sure where to look anymore. I had to just post on that "other" site for help