Draining pool from main drain

First picture, handle facing to 9 o'clock.
See where it says "off" on the tab on the handle? That is where the gate is. So handle at 3 o'clock, tab with "off" at 9 o'clock means main drain is off.
When handle at 9 o'clock and tab with "off" at 3 o'clock, skimmer is off.
 
I only need to drain a foot below the skimmer for to a nitrate problem
Nitrates are not a problem. It doesn't matter what the nitrate level is. How are you measuring nitrates and why do you think it is importamt?
 
Last edited: