As I'm getting ready to order skimmers and returns for our pool build, I thought I would ask about main drains. I always assumed you had to have one, but I've read where some think they aren't needed. Should we put one in or not?
I have main drain, and would install one again if I did it over. I'd also have two skimmers so that when the wind shifts I wouldn't have debris hanging around the diving board. Completely separate plumbing for each source to the equipment pad.
About the only thing a main drain offers is better circulation in the deep end. However, that can be accomplished by other means (i.e. lower returns or a lower wall port) so as others have pointed out, not entirely necessary. I have one but don't use it much since I have a suction side cleaner which is much better at circulation.
But one of the biggest mistakes people make on this forum is in trying to clean up a pool by pushing debris to the main drain which usually ends up clogging the drain.
when i bought my current house nine years ago it didn't take me long to discover that the main drain to my approx. 50 year old pool didn't work - it had a metal cover over it but the screws had rusted out - periodically i would notice a sulphur-like smell of sewage in the deep end - finally dumped some hydraulic cement in it and smoothed over the drain last fall when i did prep for painting the old cement pond