Water for Formula fed babies

[modsaluk]

Please could someone advise whether i should be giving my twins water they are formula fed. ~And if so how often, i BF my DS and never gave him water until he was on solids so am unsure.

they only need it if it's really hot or they are constipated

otherwise just formula is fine

Thank you MrsBadger thought that was the case but just wanted to check.