Do Pool Chemicals Expire? A Guide to Shelf Life

Have you ever wondered if your pool chemicals might be past their prime? Can they even expire? 

The short answer is, yes, pool chemicals can expire. However, shelf life varies by product, so read on for a breakdown for common pool care products. Note that for any product to maintain effectiveness it must be stored according to packaging; improper storage will shorten the life span of any product. 

Liquid Chlorine has by far the shortest shelf life, losing 50% potency within the first 6 months and 90% within a year. So, if you have liquid chlorine from last season, safe to say it is no longer effective. In fact, liquid chlorine only really has a shelf life of a few weeks before its effectiveness diminishes significantly.

Granular Chlorine when stored properly has a shelf life of up to 5 years! However, it is important that your granular chlorine does not come into contact with moisture, which can dissolve the chlorine. That's why we recommend chlorine in buckets, which are sturdy and keep your product dry for years. 

Clarifiers can also last up to 5 years. It is important to note that clarifiers are particularly sensitive to extreme temperatures. In fact, freezing will render your clarifier useless, so if you live in a cold climate you may not be able to leave your clarifier in the shed all winter. 

Alkalinity Multiplier and Calcium Hardness can last up to 5 years. Like most granular products, avoid exposing to moisture which can cause clumping. These products are pretty hardy to temperature changes, so they are safe to store outdoors as long as they are sealed. 

pH Booster can last up to 5 years, however, it is important to make sure the container its in is still intact. pH Booster is a corrosive chemical, so it may eat through its container before it expires, yikes! We recommend keeping only enough for one season on hand. 

Simple Scoop can last up to 3 years when stored properly, so if you have some from last season, it's all good! Again, it's important to avoid moisture which can cause clumping and may make your product harder to use.