but here are some thoughts a: do a search on h3po3, there are a million or so posts on the subject. b: decide what country you are in, go to google and type in 13598-36-2 (this is the CAS aka Chemical American Standard number) and your country of origin, this will bring up an amazingly high number of hits. if that doesn't work try phosphonic acid (not phosphoric) or ortho-phosphorous or phosphorous acids. there are a million different resources besides this forum that are at your fingertips, you can learn how to and should use them prior to posting here as it'll get alot fewer bees pissed off at you. yeah i know that it takes time to go through post after post after post, but you know what we're not here for you to shortcut and jump to the front of the line. you wanna know how to do this shit and do it right? then learn to fucking spend some time reading through page after page after page of document. every-one else here has done it and frankly i for one am tired of giving away knowledge to any one who knows how to use a search engine. look we're all here to help one another but if you can't even do the basics of this shit which includes reading and using a fucking search engine, then you don't deserve the info we have. maybe i'm just coming across as a pompous ass, and if so - good. when you have the basics the come back and we'll talk. till then, cheers.