As has been mentioned, a bacterial bloom in a new tank is common. And mention has been made of some causes.
To your question on feeding, if the fish are not fry (which need more feedings as they are rapidly developing) a feeding once a day is sufficient, and even missing a day or two a week will do no harm. Healthy fish can easily go a week or longer without feeding [something to remember if you go away for a few days]. They should clean it up within a minute or two. The only exception to this is substrate fish for which we drop in sinking foods that will remain there for a couple hours sometimes, as the fish pick at them. But upper feeding fish being fed flakes or pellets should consume everything offered in a couple minutes.
A hungry fish (appearing to be hungry) is a healthy fish. By instinct fish will eat if food is present, so resist the temptation to overfeed which can cause trouble for the fish as well as the tank's biological balance.
I would increase the water change volume a bit, say 40-50% once a week. Nothing is so good for an aquarium and the fish than water changes. Be aware that water changes usually worsen a bacterial bloom, but since this is not a problem for the fish, just put up with the unsightliness until it naturally clears, which it will.
And, welcome to Tropical Fish Keeping forum.