J. P. Vyas and Co. Supplies Aqua Tester with Magnifying Prism. J. P. Vyas and Co. Supplies Laboratory Instruments, Equipments, Fabricated Laboratory Glassware, Rare and Research Chemicals, Hospital Furnishings and allied Laboratory requirements. The Aqua Tester with Magnifying Prism has 15 times more sensitivity than conventional comparator methods. The Aqua Tester with Magnifying Prism has Nessler tube system. Polished plungers eliminate annoying reflections from meniscus curvature, makes colour comparisons easy. The Aqua Tester with Magnifying Prism has Built-in daylight-corrected lamp that assures accurate results.