I'd like to learn how to test for nitrogen and iron levels in water using standard lab chemicals. Does anyone know how? and/or can anyone point the way to a page on the net, and/or a book suitable for DIY enthusiasts. Regards -- Raj email: ggrk at blr_vsnl.net.in Amateur radio: VU2ZAP at BLR_IND.AS (sysop) in Bangalore, S. INDIA try http://www.khoj.com (Indian search engine)