Whenever you feel thirsty.
You should drink water or anything else that contains water because it hydrates your body
As often as is necessary.
You should drink water because if you don't drink enough water you can die
you should drink 1 liter of water per day.
water
water
Water!
Most often, water.
Although they don't drink very often - you SHOULD provide fresh drinking water daily.
Yes but it's not all that great for them, because they often urinate and defecate in it, making the water less healthy for them to drink from. If the ponds are permanent, they should be fenced off with temporary electric, making them go drink water from their waterers instead.
Should you is a question. So for example you can say 'Should you drink water'? You should is an answer/statement. So for example you can say 'You should drink water'.
Swimmers should drink drinks with lots of protein in. Or it should also be a drink with vitamins in it.