How much food?

[Sixburgh]

I currently have extensive red bubble algae covering my sand in a 92 gal. w/sump and refug. Testing does not seem to indicate that phos or nitrates are too high (.03 and <5).

I am wondering though, how much is the appropriate amount to feed?

I simply take 2 frozen cubes of frozen brine shrimp and put them in a coffee cup by the tank in the morning to let them thaw. In 30 min or so, I scoop in some tank water, swirl it around and put half into the tank. When I get home from work, I dump in the rest.

I have:
purple tang
ocellaris clown
2 bartletts anthias
bluehead? fairy wrasse
golden head goby
banggai cardinal
cleaner shrimp
peppermint srimp
~12 scarlet hermit
~10 nassarius snails
many corals

The directions on the cover say to feed as much as they can eat in 3 minutes. Mine finish it in about 45 sec.