yes those are loc lines. you can drill one hole and make it go in 2 directions, like a "y". they attach to standard threaded bulkheads, so that wont be a problem for you.
spanko, very good idea a couple of questions though:
1. if i add all new sand, wont that decrease the amount of nitrifying bacteria i have in the tank?
2. would there be a problem if i mixed old sand with new?
thanks