Thanks for the reply. I did get the Taylor K-1765 as recomended by someone on this site, and I am picking up the iron/copper kit today. I should have mentioned, because of the dry hot weather up here the stream is not flowing. I am pumping from an old (70 plus years) irrigation pond that was built in the middle of the stream. (currently not flowing). I will add what you suggested and test later this afternoon and post the results. Thanks again.