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.
One of the great features of the MJKZZ kit is the "Sync" button. For this shot, all the valves are at an even height. The Sync button allows me to delay the function of each valve so that the drops all fall at different times to get this effect. The drops are all basically the same size, however, the blue drop falls much later than the yellow one.