i am building a 18x36 kidney shape 4 ft. to 6 ft. deep with a 10x10 wading area 1 ft deep on one side. i have done everything from start to finish before except the plumbing. this is the first pool i have built on my own. i just started digging friday and will finish up with the hole monday. i was planning on 2 main drains, 2 skimmers, and 5 returns. just trying to find the best layout for the plumbing. i have no clue how it all works, lol. any help would be great.