i am building the storage system for my geo thermal hot water (125 degress) the old scholl plumbers are saying copper only. when i go th home depot or other stores they sell the "white" plastic fittings etc. these glue together and are 1/3 rd the cost of copper (i am in canada). is this pipe ok to use? i can find no information but all the information i find refers to copper

I'd recommend copper, not PVC for radiant piping.

Clarification: copper for primary/secondary loop piping, pex for the floor.

Agreed,
While anything schedule 40 should handle 150 degrees, copper is recommended for near zone process piping and my first choice.
J