Beautiful tank Mario!
You have a very nice acro and monti collection in there.
As for the dictyota, you can take all of the rock out and scrub it and it will come back... you can starve the tank and it will continue to grow... you can epoxy over it and it will grow right out from underneath the epoxy.... I've battled it before and know how much of a nuisance it can be. I found that naso tangs eat it like candy. I've recommended nasos to others with dictyota problems and everyone has had the same results. A naso will get big for your tank but you could add a small one and make plans to donate it to a public aquarium when it gets too large.