From what age should i give my baby water and how much water per day? example 25ml x 2 per day and from what age?

No Set Requirement: Age of baby not given and is needed to fully answer question. Generally there is no set requirement for water per se. Breast milk and formula provide all the water that is necessary in the first 6 months. In older babies on solids, intake of formula/breast milk is driven by thirst/hunger and usually suffices. In hot climates, water can be offered to 6 mos and older above normal fluid/solid intake.

Wouldn't bother: Water is a healthy part of any diet. Formula or breast milk is actually balanced to provide the proper amount of water equivalent, to the baby making extra water unnecessary in most cases. It is a reasonable supplement to breast fed kids when relatives want to share the joy of a nurturing moment, & extra water for a kid with hard stools is often helpful.