Spot on Notters.
It's worth remembering also that approximately 80% of our water intake comes from drinking water (and other drinks), and the other 20% comes from food.
Working hard in a hot environment and sweating a lot, I would say 3-6 litres is fine.
Whilst I find it quite interesting, I honestly don't think we need to worry about drinking too much water.
There are more deaths per year from people licking a 9v battery than there are from water intoxication.
So to put it into context for you.
If you drank your 6 liters of water over the course of the day, no problem. You could drink more if you like.
But if you ran a marathon and then drank 6 litres of water at the finish line, then you might be in trouble.
Water intoxication happens when a dehydrated person drinks an enormous volume of water at one time. It's very uncommon.
To put your mind at ease, the kidneys of a healthy adult can process about 15 liters of water a day!
I'd recommend drinking as much as you can and not worrying about it.
Kishishev has played games for Bulgaria at left back.
We've got him and Tanno who can cover both full back positions and in the event that Calde or Painter gets a long term injury, I'm sure we would bring someone in.
Matutu, Bennett and El-Abd are all full back options too. Although not ideal.