DAVE, There is another company that sells reagent test kits, EM Science at 1-800-222-0342. This topic is bigger than you might expect. There is probably 6 levels of tests for waste treatment: Color indicators strips (cost about $0.35 /test) Reagent kits w/color indicators (costs about $0.58 /test) Reagent kits w/color wheels (costs about $0.60/test) Colorimeter methods (much more accurate)(costs about $0.51/test) Photometer methods (much more accurate) (costs about $0.51/test) Titrations (very accurate) (costs what you pay a trained tech) I like the old Spect 20 photometer (340-600nm, 600-950 nm) that costs about $1200 (digital version is $1400 or the portable version the Mini-Spect 20 at $800 (battery powered) If you go upscale you can get the Spect 21 (340 - 1000 nm) for $1800 and the digital version for $2800. Many of the reagent test kits are much more accurate if you use a colorimeter to analyze the color rather than depending on your eyesight (very difficult if you are color blind). The best way we found to discover colorimetric techniques was from a Russian text on colorimetry. Seems they don't have the expensive machines we do, like AA's, so they developed very accurate color indicator techniques that work well with the old Spect 20's. They have procedures for all type of waste water analysis in many ranges that are simple to implement. Just need to find a Russian translator!! One of our process engineers was from Poland so he read Russian fluently. Just put an add in the closest university newsletter and you will find both the text and someone to traslate it for you. If you need more info, I can fax you slides from a short course I teach on inexpensive chemical analysis for electronics manufacturing. Happy Holden / MERIX Corp [log in to unmask] *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To unsubscribe from this list at any time, send a message to: * * [log in to unmask] with <subject: unsubscribe> and no text. * ***************************************************************************