I need help, I am having a new fiberglass pool/spa installed and the SPA is 18" above the pool. We are using a VS Hayward 2.7 HP Pump to run the system, the pump is set to 2700 RPM's currently or speed setting (3) and the installers have installed all the check valves and piping as seen below. On the left of the picture are the valves for the drains coming into the pump and on the right are the spa and pool return. The installers installed the check valves below the cutoff valves which is a major issue and hopefully reinstalled above the cutoff valves so we do not have to drain the fiberglass pool which would void the warranty to repair the check valves. We are going to run automation to the system but prior to getting that setup we need to fix the issue with the spa draining while the pool is in pool/spa mode to clean both bodies of water. While the system is running the spa is draining into the pool. I have been adjusting the pool return valve to try to keep both bodies of water balanced but I feel that both bodies of water should be balanced without adjusting any of the cutoff valves. I think that all the check valves installed are restricting flow on the return side. I am a newbie and my installer is loss for words. Can someone please review this post and let me know how this can be corrected? I hope someone can help us with this problem. Thanks.