why bad to lower levels too low in vinyl inground pool?

[Salvino]

I noticed in another thread that it mentioned that is was a very bad idea to drain water levels too low in an inground vinyl pool. I'm curious as to why? How does this damage the vinyl liner?

Thanks

Connie

[PoolDoc]

http://www.poolsolutions.com/tips/dont-drain-that-liner-swimming-pool.html