I have a pool with at attached ~8' diameter spa. I need to replace the eyeball fittings on the spa, which are 1.5" inside fittings (press fit, no threads). What size eyeball should I get? I see there are different orifice sizes, and I am not sure what is best. My concerns would be creating excess back pressure, creating an uncomfortable amount of 'spray', but I don't want it to be weak either. I do know that when I run the spa alone, there is more back pressure on the pump than when I run the pool alone (which leads to my next question)...
The pool itself has 2 returns, which are just 1" PVC. Is there any benefit to adding return eyeballs, or possibly some detriment?
To summarize my questions:
1. what size eyeball orifice for the spa?
2. return eyeballs or not on pool?