I feed once a day. I fed my breeding pair more often, but that is to produce a large clutch, so it should not be taken into consideration.
I find that most fish "hunt" for food during the day...wrasse hunt all the time, clowns eat pods/flatworms/etc, tangs graze......fish do get some "food" from the tank....that should be kept in mind.
Although I have at times fed up to 3-4 times per day when I had fish that needed that much.
I have also had Lyertail Anthias that I fed 1 time per day or less and looked very full and happy always.
The advice in posts above is good, although I think you need to monitor your tank for a while and adjust feeding to fit your needs....to much food will create problems for your tank (whether it be phosphates, nitrates, etc), and to little will cause problems for your livestock (whether it be sickness, death, starvation, susceptible to sickness, etc).
If you list your livestock that would help.