sani clean slime

anyone else every see ropey slimy crap in sani clean after it is a month or so old?  i mix mine into distilled water and try to reuse it for 3-5 batches (for kegging only - I use star san during brewing).  but the ropey stuff has always disturbed me, although I have never had an infection or sanitation issue to date…

[crosses fingers] [knocks on wood]

I use SaniClean on regular bases.
I mix a fresh solution each time and so far I did not see any ropey stuff concentrate.