Now that I'm a chemistry expert, I've moved on to trying to fully understand the mechanics behind it all. I'm left with three outstanding questions about my setup (see associated diagram):
1.) What is a relief & how does it affect me?
2.) This pipe was labeled PF by the builder - I'm thinking "Pool Floor," but after reviewing the pictures I have of the trench, it's an independent line separate from "Pool Drain" in the lower left corner of the diagram. Is it possible they plumbed two lines all the way from the equipment pad into the main pool drain?
3.) Why is this valve here & why is it partially closed? I have an elevated spa with a spillway into the main pool. While in pool mode, there is a small amount of flow into the spa through the jets, but clearly, the three-way valve after the heater is closed to the spa. Is the ball valve at #3 a way to balance the flow between the pool and spa through the check valve?
Thanks for the insight!