Same issue/questions came up in our design. We wanted a deeper shelf and bubblers, but bubblers seem to work best (we are told) at 9" or less depth. So this is what I did in our design (still waiting on permits). In the design, I put a 2' wide first step as the entry to our sun shelf and am going to put a bubbler right on the edge of that step. That way we get at least one bubbler in very shallow water. I still have one other bubbler on the main shelf as well in the deeper water. I'll ask for them to be run on their own lines with valves so I can adjust them independently. Maybe the deeper one we just leave off. Who knows. That was the best compromise I could come up with.
As far as the actual main sun shelf depth, we wanted a deeper one then optimal bubbler depth so we are doing 12". I would even go a little deeper than that if I could, but it's for the dogs as much as it us for us, so going much deeper than that is not practical for the smaller dogs. We did however plan for a decent amount of 18"-ish deep bench seating so we will end up with the best of both worlds.
When it came to depth, ignoring the bubbler issue, these are the questions I asked myself:
Need it shallow for little kids? - No. Deeper then.
Are we going to put a chez lounge on it and tan, thereby wanting to keep the lounge webbing out out of the water so you don't drown when face down? - No. Deeper then.
Do we want more than just the bottom of our posteriors to be wet when sitting in beach style chairs? Yes. Deeper then.
I kind of seeing us using the sun shelf space when we want to be "in the pool" but also read a book or have an iPad. For me personally, that means water up to just below my waist when reclined on a low chair. 16" is the depth I would actually go with if I could, but again dogs... So 12" it is.
plat.
