Tony,
If you are feeding that amount of food once a day, in my opinion, that's not enough. Too many hobbyists and most
LFSs totally under feed there critters. They feed them a survival amount instead of a thriving amount. What do you want your fish to accomplish, barely survive or thrive? They will do better in a home situation where you feed them that amount several times a day. Think about it, fish especially, swim constantly. they are burning off energy constantly. If, what you allow them to put into their belly is burned off, their metabolism mechanism will burn fat and lean muscle tissue.
By your picture you look like a healthy guy. How would you do on one hamberger a day, nothing else. Or, drastic example, the triplets being fed one bottle a day. It just doesn't compute does it.
And, pay no attention to the people telling you, "OH, you'll over feed your tank and cause all kinds of problems". The only way you can over feed your tank is...
to keep pouring food in after the fish stop feeding. Of course you're not going to do that, are you.
Feed your fish an amount that will promote health and growth. that means you should see fat bellys.
That's my take on the subject.
Dick