I have had problems with nutgrass growing thru my liner. We put chemicals down but within about 5 months it grew thru anyway. I am ordering a new liner today and I came across this GLI Armor Shield that is supposed to guard against nutgrass, tree roots, and other things from penetrating the liner. Adds 5 years to the liner warranty. If it will help I'm willing to buy it. Stinks that I'm having to replace my liner that's less than 1 yr old but nutgrass has ruined it. Anyone know anything about this product? Thanks!