I called the local Hotspring dealer and couldnt talk to a service guy but the man on the phone said that he thinks they use regular PVC cement for everything. I called another repair place and the guy said they use blue flex PVC cement ( which I cant find) for everything. He said if its under pressure, you need the flex cement even on hard PVC joints. I need to fix a joint where a piece of flex goes into a reducer which is hard. I was going to glue a piece of hard PVC to replace the piece of flex that I cut and then put the flex into it. Do I need a different cement for the hard to hard then the flex to hard? Should I use purple primer and reg cement or flex cement? Is there a special primer for the flex cement?
Thanks

In a perfect world you'd use WELD-ON 795(flexible pvc to rigid pvc glue), after applying either clear or purple primer.

Watkins(hotSpring) has used a number of different glues over the years, especially when VOC emmissions were under scrutiny in California.

You'll be fine if you primer the joint and the pipe then apply your glue to both as well. It doesn't matter much what you use for glue, just let it set up for at least 24 hrs.