You may see images that are larger - which means they will occur sooner. Smaller images in the background will take longer to manifest - if you are seeking personal information. One other method of scrying in water is to place a dish of water in a darkened room, lit from the sides by two candles. The dish in this case should be a solid, neutral color. If you are using a crystal select one that calls to you.
Most people prefer a crystal ball or crystal sckull.
The crystal must be clear quartz - a larger crystal is best. The crystal will seem appealing to your eye. It does not have to be your 'personal crystal'. The crystal can be clear or have inclusions in it. Many have rainbows.