Sue44, first of all, thanks for posting the reply regarding your success with the Sweet Air roof vent filters.
Now, regarding the issue of the impact on septic system performance when using chlorine bleach in your laundry. I read an article in the PipeLine publication of the National Small Flows Clearinghouse (NSFC) regarding this issue. The conclusion drawn from a study of the use of household cleaners and disinfectants was that if you follow the label directions on the container, the septic system is able to assimilate the small amount of chlorine, and other antibacterial substances that are applied under normal use circumstances.
You can read this article by visiting the NSFC Website, and clicking on “Publications”. The website address is:
http://www.nsfc.wvu.edu
You may have to search around on this site to find this specific article, but it is there. I think that it was published in 1999. JWA