Be aware that Future or KLEER WAX also mixes VERY WELL with acryllic paints... this can be good and bad..
If you underlying coat of paint isn't fully cured (not just 'dry to the touch!'), then applying the wax may well take up your paint.
If you are trying to make water, you can make small batches of darker green/blue/grey to incicate deeper areas of a streem or creek, and then add beige and tan to show a lighter area of shallow water (near the banks of the stream, for example...)
Also - if you are trying to make "water"..... never apply more than a 1/16th or so deep of your wax... otherwise it will take forever to dry, and it will more than likely crack after sitting out on a diormama ch... let this dry for 3-4 days before adding extra coats.