Nextteq LLC, of Tampa, Fla., introduces the Gastec sulfide ion in Liquid Detector Tube No. 211. This detector tube provides an accurate, cost effective, quick and easy method for detecting hydrogen sulfide levels in water and wastewater. With a broad detection range and simple sampling procedure, it’s quick and easy to use, even in the field. The direct-reading liquid detector tubes produce a quantitative color stain that quickly pinpoints problem areas in just two to three minutes.