"もっと水がほしいです。"

Translation: I want more water.

[SkyOwlKey]

I find myself saying this a lot with this weather lately.
とても暑いですよ！

[sora_Japan]

In your place? My place, too. Too, hot.

[KanKanMikan]

haha same but i always said: 暑いな～

[MotYLi2]

Does "hoshii desu" in Japanese sound as rough as it does in English or is it formal enough? (Would you use this structure in a restaurant instead of "mo chotto omizu o kudasai" for example?)

[S_jp]

Surely ほしいです is a bit rough and childish.
いただけますか is very polite expression to require something.
(いただく is of いただきます(Japanese greeting? before eating a meal))
But be careful not to just replace ください with いただけますか.
Because もっと is also childish expression, i feel もっと水をいただけますか is strange.
I use おみずをもういっぱいいただけますか in restaurant. (もういっぱい one more cup of)

[FreakensteinAG]

Hoshii feels like a demand, you wouldnt use this word with strangers or even acquaintances. Too rude.

[Rob996895]

"I"d like to have more water" should work too. Shouldn't it? !

[Yakuul]

How would say, "I would like more water" or is it simply polite enough to say it this way to a waiter?

[Nana.san]

Motto... NO.. I AM NOT HENTAI... heavy breath

[sus_crow]

HENTAI