Becky, think vertical! Did you see my living wall that I made out of an old shutter? I would think you could grow succulents/sedum etc. on a living wall on your balcony there, they are very forgiving. And yes, the "Y" coupler should work well for you, I have one on my hose bib in my shade garden... one for the drip system that I just installed, and one for my hose to water all the stuff that's not on the drip system. They are cheap, I think I got mine at Walmart for less than $3.00. Here's a pic of the living wall to inspire you... it's grown quite a bit since this pic was taken, time for some new pictures!
