As per GSB we only no food fast for vaikunt ekadashi and shivratri ..very few people do nirjal ie without water. I can't imagine this. So I do have warm water through the day. Not really sure about karvachauth
Shivratri night go to the temple take 108 peadakshina which takes about 4 hours. Full night bhajan then morning go have bath come back to temple break the fast with prasad and go back. Usually I am working so without water it is impossible.
Navratri it is one upvas meal and fruits for 9 days. Slightly tough when u do for first time
But water I do drink all through the day. I have a job a fam and baby to look after 🙈