There’s a long-standing opinion that tea is dehydrating, and so can’t replace water in your daily fluid intake. But research has shown that to be false.
It turns out that a moderate amount of tea (say 2-3 glasses) can count toward your daily quota. And as a bonus … tea contains beneficial antioxidants that water doesn’t! Just be careful that you’re not also adding lots of sugar and other non-beneficial ingredients (i.e. bottled teas).
So while you really should be drinking water every day, there’s no reason why you can’t add a few cups of tea as well.