This kit tests for Sulfite using the drop count method. Range and sensitivity is 1 drop = 5 ppm SO₃^2-.

The Model AR-42 has the same test range for pH, Hardness, and Iron as the AR-02, but it also is equipped to test for Sulfide (0.2-20 ppm). Includes 50 tests for pH, Hardness, and Sulfide; 100 tests for Iron.

A creepy, crawly, wet investigation of the health of streams, ponds, and other freshwater environments. Following the easy-to-read BUGKIT manual, one to two students learn to collect, observe, sort, and identify aquatic insects as a tool for measuring water quality.

Students can complete the activity at home after collection or spend an afternoon outdoors beside a stream. The BUGKIT includes mesh leaf bags for collection, trays and plastic dishes for sorting, a magnifying lens, BUG GUIDE, and a BUG BOARD identification chart. Ideal for bug-hunters, age 8 and up.

This kit tests for Alkalinity using the dropper bottle method. Range/sensitivity is 1 drop = 10, 25, or 50 ppm as CaCO₃.

This kit tests for Total Hardness in water by using the Dropper Bottle Method. All results are as CaCO₃. Range/sensitivity is 1 drop = 10, 25, or 50 ppm CaCO₃.

This kit tests for Sodium Nitrite using the Direct Reading Titrator method. Range/sensitivity is 0-1000 ppm/20 ppm NaNO₂.

TesTabs^® kit for measuring pH. Ideal for younger students and teachers who would like an alternative to liquid pH indicators. Ideal companion to Soil NPK Kit (Code 3-5880).

• Simple diagrammed instructions
• Laminated color chart
• 50 tests for pH
• Wide Range 4-11 in 1.0 pH units
• Distilled or deionized water recommended

Determine turbidity or degree of visibility in natural waters with this weighted 20 cm diameter disk.

• braided line
• marked every half-meter up to 20 meters

This kit tests for Tannin/Lignin using the Octa-Slide 2 Comparator. Range and sensitivity is 1, 2, 3, 4, 5, 6, 8, 10 ppm Tannin or lignin like substances.