MJKZZ Water Drop Kit
... It is now my system of choice for water drops and highly recommend it for this type of photography. In my opinion, it offers the most affordable price on the market, in exchange for a product that has many features.
... It is a very versatile water drop system. One of the great features of this system is an IR remote controller which activates the main control box. This remote controller fits easily in your hand and measures 8 1/2cm x 4cm x 5mm thickness (4 1/2" x 1 1/2" x 1/4").
...There is available a one valve system, a three valve system and now one with six valves. Each system is designed to do at least three drops or more for each valve.
...You can check the Flickr MJKZZ group and see how people are progressing and read the discussion topics - http://www.flickr.com/groups/2375554@N25/
...Always lots of new features - http://www.mjkzz.com/products/waterdrop.html. The developer has done many upgrades and accessories. Check it out.
Another great feature of this system is a purge function. With a couple of button presses, you can put some liquid through the valve to get rid of any air bubbles, or completely purge the bottle of all it's contents and replace the liquid with another colour without disturbing a thing.
It's also a recommended way to clean the valve with warm water after a shoot.