Drainage problems are such a pain. From what you say, it sounds as though the water collection comes from the drainpipe leading from your patio, correct? A couple of ideas come to mind: you might look into extending the drain pipes so the water drains to an area where it doesn't create problems. Or you might look into creating a French drain. You could Google these ideas online and see if they make sense for you.

Well you got the 1st lesson of pool ownership. 1) Becareful of the "pool store" and what they say. They don't always know what they are talking about. Buy a test kit, learn how your pool is suppose to work. Do your own testing. Post your pool chemical test results here and we can tell you what to buy. Also, if I were you, I would attack one problem at a time. One change can effect other factors without ever having to add the second chemical. And, don't worry, you have NOT ruined your pool. When you mix the chemicals together, it "can" basically make them "ineffective" at doing anything so when you end up adding what you have mixed up, the chemicals do nothing or less than what you bought them for in the first place if they react with themselves. So what you did was waste time and money and probably changed your pool chemistry less or not at all compared to if you had added them to the pool separately. The pool chemical company can sell you a bunch of chemicals to attack meaningless problems and many times they set themselves up for you creating additional problems so you can come back and buy more chemicals. You need to know whats going on and go to the store with one chemical and process in mind to buy and ignore the temptation to ask them anything. ;)

What is a water sprout? Do you have a septic system in the yard? You could have a leak in a water line, a high water table or it could just be an area that doesn't drain well. How much rain did you have the day before? I would leave the hole open for a few days and see if the water continues to collect. If it starts drying up, then I would suggest using plants in that area that like wet feet. If it continues to collect water you need to identify where it's coming from. A water line, or sprinkler line, may have been damaged during the patio build.

I was going to say that head planter would look great with lemon coral sedum. It does well in full sun or dappled shade and doesn't need much water or hens 'n chicks or that really brightly-colored creeping jenny (it does well anywhere). I agree with above about coleus too. There are so many color variations you really can't go wrong. What about some of those huge New Guinea impatiens or sunpatients (the ones that can take some sun). Mona lavendar is cute and does well in morning sun. If you haven't used Ptilotus Joey yet, you really must! It's so cool looking. It does like full sun but may do okay in part sun.