I use a plastic bag full of water then prick a tiny hole in with a pin, the drip is constant so you can get a better idea of timing. I want to try with some colouring in the bag dripping into clear water, I reckon that might be quite cool.......when I light I bounce a Flash off a card set behind the water container usually a developing tray, the card can be any colour so reflects the colour into the water.
I've used oil too from a syringe.all fun to do.
Great work Glen