I have a Dictyota problem in my tank. I don't mind it too much since it is the iridescent blue type and it keeps the other algaes at bay, but it is starting to get out of control. The emerald crab doesn't touch it. I have found that if I let it grow out it detaches from the rock and I can pull big chucks out with no effort. A couple of days ago I purchased a golden head sleeper goby and some red leg hermits to help keep the sand clean. Well apparently they both like to eat Dictyota. Out of 10 crabs I have see two eating the algae, it is high in the tank so I think some haven't found it yet. I noticed the gody munching on the Dictyota yesterday and did a double take. I was so amazed I grabbed my iphone and took a video (post later when I'm back home). He was going to town on this stuff. Not sure if he is interested in the Dictyota or some organism on the Dictyota. But I didn't see the Dictyota coming out of his gills so that is a good sign. It will be interesting to see if these guys can control the growth. I need to do some manual removal this weekend and let them try to control the rest.

Anyone else noticed a goby eating Dictyota or another macro?

Wow, that's VERY interesting!!
I've never heard of this before, but I've had personal experience with how Dictyota can just take over and go nuts.
I have an Acan frag that the stuff is constantly growing out of.
I got desperate enough to put superglue over all the spots I could see it growing from (dabs of superglue right between Acan heads!), but I noticed a new sprig of Dictyota popping up again the other day.

my emerald loved the stuff *shrugs*

irridescent blue you say?

It looks something like this

OK the video is waiting in line on vimeo, it should be available to view soon. Here is the link:
http://vimeo.com/9418853

I really need to clean the glass!!