My pool is getting a new 27 mil Pacific liner today. Pool guy is telling me we have to use his brand of chemicals to ensure no damage to the liner. He is also telling me using any other brand or generics voids the liner warranty. Is there any truth to that? Sounds like a sales scam to me but has anyone gone after the liner manufacturer for a defect and had this challenge? I am adapting the BBB method so I am not sure how that plays into the warranty.