If your 1080ti is only making $1 a day you are doing something wrong. I know people running a single 1080ti and they are making $3-$5 per day. Where are you getting your information or what are you mining and on what settings? That $3-$5 per day figure is without running the card intense, unless you consider 65c and 76% TDP to be anything except conservative.

You're doing something wrong if your goal is primarily to make the most $ per day. Maybe we can help you figure it out and optimize.