A couple of notes on bleaching... 1) Once you have bleached the shells to the desired level, you need to soak in fresh water until all of the residual bleach comes out. You may need to change the water a couple times in this process. Otherwise the bleach will form chlorine crystals one it dries and these will stay in the shell and deteriorate it over time. 2) For years I wondered why bleaching did not seem to work on some shells. A chemist friend of mine clued me as to why about a year ago. Well, it was not specific to the shells, it was because of how I treated the shells first. Often I would wash an scrub the shells first, even soaking the in soapy water for a while. The soap (detergent) I was using is Dawn Dishwashing Liquid. Turns out that detergents such as this one have neutralizing effect on bleach. ... and even though you rinse of soak the shell, the agent apparently stays in it. So a simple green algae spot on a shell may not come out. .. therefore if you want to bleach, don't wash your shells with "detergent" dishwashing liquids. Dishwashing "soap" like Palmolive may not have the same negative effect (unknown) Best Regards, Leslie Allen Crnkovic HARF-IMCS Natural History Books § Specialized in Sea Shells & Marine Sciences § New & Used Books & Journals § Buy § Sell § Trade § [log in to unmask] § (713)784-7084 § (713)598-7084 Cel ---------------------------------------------------------------------- [log in to unmask] - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ----------------------------------------------------------------------