Set the time ahead at least three hours on your device and then return to the game and collect all the water. Close the game but do not minimize the app. Now when you set the time back to normal and open the game again you will have the extra water. This trick can be repeated as many times as desired.
Tap on the 'Bank' icon and hit 'Free Gems' to complete several offers on Tapjoy that will earn you free diamonds.
Bonuses like diamonds can be earned by simply entering the promo code of another player or have them enter yours. Promo codes can be obtained by tapping on the lower left on a gear icon and hitting the 'Promo Code' button.