How long does polyelectrolyte last?
Shelf life of polyelectrolyte powder in the bag and of the solution in the tank, the signs of ageing, and how to stock without waste.
Powder in a sealed bag
Granular polyacrylamide is stable when it stays dry. Sunfloc grades carry a 24-month shelf life in the unopened pack, stored between 0 and 35 °C away from rain and direct sun.
Liquid Sun Brand polymers differ by product: SunMac SC04 and SunDec SC05 are 24 months, SunRedep SC03 is 12 months and SunRedep SC10 is 6 months, all in closed drums.
Once the bag is opened
Polyacrylamide pulls moisture from the air. An open bag left in a humid store soon forms lumps that dissolve slowly and leave gel particles in the tank. Fold and clip the bag after each use, or tip the balance into a closed drum.
Solution in the tank
Made-up solution has a far shorter life than powder. The Sunfloc spec sheets give solution stability of about one day in deionised water. In practice, make up what the plant will use in a shift or a day, and do not top up an old batch with fresh solution.
Signs a stock has aged
Hard cakes in the bag, powder that will not disperse, a solution that is thinner than usual, or flocs that are smaller at the same dose. If you see these, run a quick jar test against a fresh bag before you raise the dose.
Stocking without waste
Use first in, first out: date the bags on arrival and issue the oldest first. Order in quantities the plant uses well inside the shelf life. For low-use sites, the 10 kg MQ packs make that easier than 25 kg bags.
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Read →Not sure which grade suits your water?
Send us a one-litre sample or describe your process. We test it in our lab free of charge and recommend a grade and starting dose, and quote within 1 business hour.