Sorry. The post I'm responding to was back in Dec. 05. :) I had one of those air purifiers - the one from Sharper Image. I stopped using it when I noticed problems with my 5 fuzzies within a very short time after hooking it up. There was a lot of hacking and coughing from 3 out of the 5 when there had been none before. Once I left it off for a day, there was no coughing. If I turned it back on again and let it run--coughing/ gagging/ etc. I ran through many scenarios: my room was "not too small", it was not "too close to the cage". Everything they said to try to fix it didn't change their situation. The only thing that stopped their hacking was turning it off for good. Just to pass the info along! Michelle and the fuzzy5 [Posted in FML issue 5129]