Did the PB tell you the brand name and model? If you get that information, you can research directly from the manufacturer through their installation manual (would be on line on their site) what the criteria is for best set up.

Most of the equipment manufacturers make their installation/operational manuals available on line.

They did not give me a brand, but I've researched on my own all the options seem to work in various depths between 4 and 10 inches. It kind of seems to me like the PB just doesn't want to do a bubbler w/ lights, but I don't understand why. And our sales guy just blames it on the design team, saying "They always make us adjust the depth to 5" for lighted bubblers."

Not sure why the pic didn't attach, trying again. This is what we want. It will only be one lighted bubbler in our design.

OK. I would push for a brand just so you know and it's shown in the contract. I am very detailed with my contracts to my listing item names and models.

We have done bubblers before and there is a specific flow rate required so it works properly. The flow rate is dependent on the pump size used, the pipe size and how far the pump the bubbler is located. Deeper water requires more flow as there is more resistance. For shallow water, there's less resistance.

We will install a "bleed line" from the discharge side of the pump to divert water directly back to the pool to allow for regulation of bubbler height. A 3 way valve is used to accomplish this.

Sounds like the salesman is passing the buck.

Hope it works out well for you.

Thank you so much for the info. But where I'm still perplexed is that I don't understand why they are willing to do a bubbler in 6" of water, but not a lighted bubbler. Is there a big difference?

Ask them directly. The lighted bubbler may have specific install requirements.