I need help on how to color water and make bubbles for a bathtub cake. I'd prefer not to use fondant for the bubbles. Thanks!

I'd add just a tiny touch of black and blue to piping gel for the water.
To make bubbles use a round tip and pipe dots. The bigger the tip &/or the harder you squeeze the bigger the bubble.

I just dont now about the bubbles. If you added the right airbrushing colors like various shades of gray, blue, silver and white I bet they would be very believable over BC piped dots.
The water idea using the piping gel is a great one. I also understand you can make a sugar syrup tinted with blue and pour it on but it is really a tough trick to master. I have not tried either one as yet but I so want to see ho yours turns out! My curiosity is peaked!

Not sure if this is anything like what you are looking for but here is one I found on the Wilton site:

http://www.wilton.com/idea/Bubbling-With-Excitement-1

OR:

http://www.wilton.com/idea/A-Splashy-Debut

Hi I made the bathtub cake for a baby shower. I used large and small gumballs and stacked them, and "glued" them with white icing. Then they could be eaten, and looked great since they are shiney and the right size, good luck, I can email you a pic of mine if you are interested let me know [email protected]

figured you would know this but used white gumballs, got them at a local candy shop where you can pick your items also Walmart and toys r us sell them!

The gum balls are a great idea!

here is a cute one also. Pipe b/c bubbles using #10 or 12 tip.



http://familyfun.go.com/recipes/just-ducky-tub-cake-686541/

this is a great one


http://www.flickr.com/photos/25863947@N05/3741974856/