The only frozen food I feed now is LRS Reef frenzy and Fish Frenzy.I believe is the cleanest frozen food available.I use to use a variety especially Rod's Food which is messy in comparison.
Twice a week frozen and the rest a variety of sinking pellets from Coral Frenzy,New Life Spectrum and Fauna Marin.What the fish don't eat sinks to the bottom where the nassarius snails,ceriths,sexy shrimps and fire shrimps take care of any leftovers.Those pellets make great LPS foods as well.Maybe in the past but I don't buy into pellets adding any more phosphate then frozen.Anything left to decay will cause phosphate.With all that said,I still wouldn't use flake foods.