Woah oh oh, I drink around 3L per day and I thought that was heaps!
I used to not need to drink this much water, but over a few weeks I started drinking more and more water each day and now I get thirsty sooner.
My skin has always been very clear and I didn't notice a difference, but I do think that by drinking water regularly and getting enough sleep contributes to having clearer skin.
That is a lot. Although it's pretty rare to die of water intoxication, that mainly seems to happen in drug related cases or when water is consumed in a short amount of time. I'm sure drinking 3l throughout the day at a paced rate is completely fine but not really necessary and could have an adverse affect on your bladder and kidneys..