To avoid getting kidney stones, make sure that you drink plenty of water each day to avoid becoming dehydrated. It is very important to keep your urine diluted to avoid waste products forming into kidney stones.
You can tell how diluted your urine is by looking at its colour. The darker your urine is, the more concentrated it is. Your urine is usually a dark yellow colour in the morning because it contains a build-up of waste products that your body has produced overnight.
Normally, you should drink at least six to eight glasses (about 1.2 litres) of water each day. However, people who have had a kidney stone before are encouraged to increase their fluid intake to two to three litres each day in order to ‘flush out’ waste products that can cause stones to develop.
Drinks such as tea, coffee, and fruit juice can count towards your fluid intake, but water is the healthiest option, and is best for preventing kidney stones developing. You should also make sure that you drink more than the recommended daily amount when it is hot, or when you are exercising, in order to replenish fluids that are lost through sweating.
(Source: hse.ie)