Like all perishable goods, pool test kits expire after a certain period. If a pool test kit doesn?t come with an expiration date, we recommend discarding the bottle 180 days after you have opened it. 
Pool test kits have become an important part of a swimming pool store supply since you can check the quality of the pool water before diving in. For instance, if the swimming pool has high chlorine levels, it alters the pH level of the water, making it more acidic. This can cause skin and eye irritation while proving extremely uncomfortable. 
In this guide, we have discussed everything you need to know about pool test strips.
Can Pool Testing Reagents Go Bad"  

Pool test reagents go bad because they have a limited shelf life, but they can last longer than regular pool test strips. Normally, pool test strips last for a few months till they become unusable. Many pool contractors claim that chemicals can last for almost two years without getting expired. But there are a few factors that can reduce the lifespan of testing chemicals, which are as follows: 

While storing them in large bottles, make sure the bottles are clean 
Prevent dust and contamination to maintain the chemistry of the pool test reagents
Check the expiration dates of the test kits to make sure you are purchasing the newest kits
Don?t leave the testing kit in the wrong conditions, such as high humidity, moisture, etc. 
Low-quality or cheap test reagents don?t last long. 
Keep pool test strips away ...