What is the shelf life of Pennant Magnum once it is opened? A gallon of this would be a ten year supply for me.
Pennant Magnum, like most of our other concentrates, should last for years and years on the shelf. Most manufacturers give a shelf life of at least 5 years, but products can last longer if you keep the lid on, keep the product out of direct sunlight, and shake up the container every few months to prevent the active ingredient from settling to the bottom and getting clumpy and dried out.
Answer last updated on: 05/29/2011