Brian,

I can't compare with your 30w cause I have a 100. But the ratio I drop to do acrylic from glass is about 75% less the power I use on glass. I keep my speed the same. On a 1oow I use 95 power and 90 speed. On acrylic I use 23 power and 90 speed. Approximate drop of 75% in power using the same speed. Mybe on your 30w try 20% power using the same speed. Acrylic typically looks more frosted than glass. I kind of like acrylic results more than glass results. Good luck!