It depends on the type of fish how easily you can get away with this feeding schedule. Since fish are not warmblooded most are able to survive on this convenience diet kind of approach for a long time, others will definitely not have enough reserves in times of stress. Just please don't ever get seahorses. ;)

Here's an article that has (in my opinion) a lot of excellent info in it in regards to both food as well as algae management:
http://reefkeeping.com/issues/2002-07/eb/index.php