You want lots of natural light but set your flashes at the lower end of power so they don't flash so long. High speed sync helps and lots of patience.
Google produced this:
"To actually get an "exposure", a flash is fired. The flash light duration will now become the actual
SO now we need to see how long does it takes the flash to fire. It turns out that the output power of the flash, actually affects the duration of the light, so to get exposure times. If you need exposure faster than 1/6000 seconds, the output needs to be reduced. For more information on the light duration please see the test I ran on my Sigma EF-500 flash." http://www.diyphotography.net/light_...s_output_power
You need enough background light and flash to illuminate your object and nothing else, otherwise you are wasting power. I'm not sure but I think this is where a large guide number will help. As you decrease the power the range decreases and eventually will fall short of your bowl of water but you will have a very high effective shutter speed.