Mikey
Aspiring Old Fart, EE, computer & networking geek
I use Hach for both total (http://www.hach.com/single-paramete...7639974545&secondPageNumber=1&pimContext=USen) and free (http://www.hach.com/single-paramete...7639974595&secondPageNumber=1&pimContext=USen) chlorine. Pricey but I trust them.