water effect in cocos2d

Question

Hi, I'd like to have a water effect on a background layer in my app. The effect doesn't need to react to touch or anything - it just needs to wave an image a little bit.

CCWaves3D seem ok, but leave have nasty black artifacts around the edges when I run it. Similarly CCShaky3D. CCLiquid brings my app down from 20fps to 5fps..

Is there any other effect I might want to try out? Or perhaps I'm using the current effects in a wrong way?

id shaky = [CCShaky3D actionWithRange:4 shakeZ:NO grid:ccg(15,10) duration:4];
id liquid = [CCLiquid actionWithSize:ccg(15,10) duration:1];
id wave = [CCWaves3D actionWithWaves:18 amplitude:80 grid:ccg(15,10) duration:10];

Bonus question - where can I find any good documentation for cocos2d effects? I found default cocos2d docs utterly useless & wasted a couple of hours trying to google before asking this question :/