PEX tubing has zero warranty for pool water applications
PEX Tubing Banned
PEX tubing is banned from pool water useage in the United States and Canada.

The Plastic Pipe and Fittings Association asserts in their INSTALLATION HANDBOOK:
Cross-linked Polyethylene (PEX) Hot- and Cold- Water Distribution Systems, under Limitations on PEX Use, bullet point six: Do not use in swimming pool piping systems.

PEX tubing is a great product for it's intended potable water plumbing systems usage, in home plumbing systems, but pool water chemistry can damage its physical integrity. It has zero warranty because of its incompatibility with pool water chemistry.
IndekSolar© is the most suited product for pool water use. It is produced, using the finest polymer resins, engineered for pool water.
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IInDekSolar© tubing warranty