How to dilute apple juice

I have been introducing my 16 month daughter to apple juice by giving her 2 oz. of juice with 6.5 oz. of water to make an 8.5 oz. bottle.  Within about a week and a half she went from drinking about 28 oz. of milk/formula to only drinking about 4 - 7 oz. a day.  In place of previous milk, she now asks for apple juice.  She is drinking about 4 -5 bottles a day, again it is diluted, so she only drinks really 8 - 10 oz. of juice and 26 - 32.5 oz. of water.  I recently heard that too much water can cause an imbalance in the cells and cause issues with development, is that true?  Should I be diluting it less?  I don't want her to get too much sugar and diarhea (diarrhea).  I also wonder if cutting down on her milk so rapidly is normal??  Can she still get enough fats for proper growth and development without lots of milk?  She is chubby, so I am not worried about her weight, but I do not want her brain development impaired due to an improper balance of fats and nutrients.

[BeeFree]

You do not have to change the ratio of apple juice to water (and shouldn't as this will cause diarrhea or an overly-acidic stomach), just decrease the amount of liquids you are feeding her in total. Most children will let you know when they are hungry or thirsty and the amounts they need depends on weather/temperature, but a general amount is 8-10 ounces. Water intoxication is a risk when you continuously feed your child water all day long, which is not needed at such a young age. If there is too much water in the cells, they begin to swell and can disrupt their growth.
It is normal for children to choose juice over milk or formula in a short period of time, just be sure she is still getting her recommended calcium needs per day.
Sounds like she has a wonderful mother!
Babycenter.com is a great site for this type of information.

All the best.