Bests & Worsts Reviews from Amazon

I first ordered 2 boxes of these filters and initially thought they were great, enough that when I opened the second box, I went ahead and ordered a third one. You see, we have 2 fountains and 4 cats so we go thru filters! It was when we began using the second box we noticed a white bubbly foam would occasionally develop. I'd rinse and wash the fountains and replace the water. Then we started seeing a pink-orange discoloration on the filter itself and sometimes on the back side of the flower stem of the fountain. Very strange. Decided that probably wasn't good for the kitties to drink, so again I cleaned the fountains and replaced the filters, using fresh water of course. This last time was a little over a week ago and they refused to use one of the fountains the very same day! That was the fountain on the second floor, nowhere near their food, do that wasn't causing the problem. Today I decided to clean it again and replace using another new filter, even tho the old filter was only about 10 days old. Again, I saw the orange discoloration on the filter (see attached photo). This time I cleaned the fountain and replaced that filter with the Catit brand name filter and our 17 yr old lady Norma Jean, went over, sniffed around it and drank from her fountain again! She had been refusing to use that fountain for over a week (I got tired of her drinking out of our bathroom sink). I have no clue what is causing the orange discoloration... we're thinking it might be the water-softening agent. Whatever it is, I don't want our kitties drinking the water from these filters. I have returned the 3rd box to Amazon and am searching now for the previous design that had only charcoal in the filters.