one of the first test I would do if i were you would be the CYA test. if your CYA is high, your chlorine is going to have to be high too. I was using the trichlor pucks in a feeder when my pool was first finished. after a couple of months, my CYA was up there. I have not drained my pool, but i keep my chlorine at around 9-10 ppm. my CYA is between 80-90. I learned a calculation from TFP where calculate your chlorine level to be 11.5% of your CYA level. this winter, i may do a partial drain to get my CYA down for next summer so that I can keep my chlorine at a lower level at around 1.5ppm-3ppm. Do walk, run over to TFP as fast as you can. I swear they can and will help you to get your pool perfect over there.

Thanks Avanti. Thinking about it again, it might make more sense to have the linear drain at the blue line (against the long wall), because if we had it at the red line, that would mean I'd have a step down crossing the threshold (drain location would be the lowest point in the shower), defeating the purpose of doing a single-sloping shower...

Thanks, @Yardvaark and @Tara for taking time to check this out. I definitely would like to get it by the house, but I don't think there is a spot for it. I don't want it to be blocking a view from our screened in porch either. The real picture is a bit misleading as it's giving a confusing perspective in regards to the porch. The porch is an extension of the house. It's not contained within the footprint of the house. Also, the drawings weren't really to scale. The hot tub pad will be 10x10 while the pergola is only 7x9. But none if it is to true scale. We don't want to put it under the pergola as we have a really nice seating area under there that we want to keep. The other idea I had was to take the privacy fence along the side of our house and push it back about 8 feet towards the front of the house. Then the hot tub could go here. The advantages are that it would be closer to the house which would be nice for the winter! However, it would be a bit tucked away and I feel it might be too sandwiched between the fence and the house for my liking.

My first thought was on the stairwell wall also. You'd have to get your cable or whatever wire to that wall though. What is behind the sectional where you are taking the picture from? Kitchen?