Is main drain necessary?

[JimK]

Checked FC this morning....no FC loss overnight.

Concerning the main drain, it does seem that throttling down flow through the MD has improved skimmer performance. That said, I'm not sure I'd want to be completely without one. There are times during late spring when the trees are dropping a lot of stuff and the skimmers clog up while I'm at work. With the MD there's still water flow preventing damage to the system.

Perhaps during times of lots of debris falling into the pool I'll keep the MD open and close it off the rest of the time.

[CarlD]

Just my 2 ¢... I have a 5 1/2' deep end, a 40' long pool, and only a low side-wall drain and skimmer at one end and it does fine without a bottom drain.