Question: how much water should a 65 year old man drink per day?
Answer: Again, the recommendation for older adults is to consume at least 1.7 liters/day, which corresponds to at least 57.5 fluid ounces. In the US, where a measuring cup = 8 ounces, this is equivalent to 7.1 cups/day. Keep a journal to record how much fluid your older parent is drinking.