Ok, 1/20,000th of an inch of unprovable hearsay? Confusion happened, but its all in your head.
Since you appear to be having trouble, I'll spell it out for you.
1. You claimed water remains "flat" at rest, citing a pool and a lake as proof.
2. I pointed out that these are not proof, because the curvature over them is small enough that it can't be detected without incredibly sensitive equipment anyway.
My memory was off, and it's actually larger than I remembered, but my point still stands. Based off the assumed radius of the earth of ~4k miles, a 200 foot pool would have a curvature of 1/100th of an inch. So no, you can't claim "I looked at my pool and it was flat!" as "proof" of anything.