When using test kits and reagents, it’s important to keep them in the proper condition so they can do their part to maintain water quality. First and foremost, to avoid contamination and preserve freshness, always follow these three basic guidelines:
- Keep reagent containers tightly closed
- Never interchange reagent caps
- Wipe all equipment with a clean, dry cloth after use
Make sure the color comparator is in good condition. Check for cracks, faded color standards, moisture between printed standards and the clear acrylic protector, or any staining in the test cells that can’t be removed with diluted muriatic acid. These are signs that it’s time for a comparator’s retirement.
Examine any other test vials to ensure that they are clear and uncracked. Any missing caps and instructions can be easily replaced.
Keep all test kit components in their “home” — a properly labeled case. Make sure the lid securely fastens and the kit is kept out of the reach of children. For storage, test kits do best in a cool, dark place and away from treatment chemicals (especially chlorine and bromine). Direct sunlight, temperature extremes, and exposure to volatile treatment products will shorten their useful life.
Ideal storage temperatures for test kits are between 36°–85° F (2°–29° C), preferably in an environment without big temperature swings. But you ever must choose between a hot outdoor garage, storage room or vehicle trunk and the refrigerator, opt for the latter for longer-term storage. Keeping reagents in the refrigerator can prolong shelf life. However, once they are taken out, they should be used because subjecting them to constant fluctuations in temperature will cause them to degrade faster.
Because environmental influences can diminish a reagent’s effectiveness over time, it’s best to replace all the chemicals in your kit after one year. If your testing is seasonal, start each season with fresh reagents.