Wanda, are you ok? Would you like someone else to pick a subject>

I have three rocks running off one pump. I measured the rocks and then asked the pump seller to recommend the size of pump. The first one wasn't strong enough so I returned it for a stronger one. DH made a three prong T with PVC pipe to split water to all three rock columns.

I built a backyard pond-less stream with little waterfalls from this information. https://www.familyhandyman.com/project/build-a-backyard-waterfall-and-stream/ I originally had a leaking pond that the previous owner installed. II filled it in and built a small stream and a basin where all the water is under rock so there's no standing pond water. My upper basin is covered as well so that I don't have to worry about my dog taking a swim there either. It was a ton of work, especially digging the lower basin out. But I get lovely sound of water and frequently see the birds taking a drink. It would have been significantly more expensive if I hadn't already had all the rock from the previous pond. The liner alone was the next most expensive at several hundred dollars. I did all the labor myself. This one looks really interesting from the same site. I like how compact it is. I needed to fill a big space so the stream option worked for me. https://www.familyhandyman.com/project/backyard-waterfall/

Sorry I can't help you with your question on the spa. Personally, I don't care for spa's that are attached to the pool. We opted for a separate, above ground hot tub/spa that we had placed near the pool. It was easier to care for it, had more jets (we wanted it for therapy), cheaper to keep it warm/hot and located it just outside our master bedroom. We actually had it recessed into the ground a couple feet and a masonry bench built around it on three sides which then became additional seating as well as a place to put snacks, drinks, and towels. It also made getting into and out of the spa a lot easier as you only had to sit on the bench then spin around on your butt. The spa is that brown thing just beyond the basketball hoop. It has a cover on it to keep the water warm and clean.