Rule 1: DO NOT OVERFEED
Overfeeding kills more tanks than you realize. Whatever you feed your fish, eaten or not, ends up as waste in your tank. Take a days portion of food and let it set overnight in a cup and smell it the next day. You'll see what I mean. Think how much waste is in the tank after a month, a year, or more.
All waste goes through the ammonia/nitrite/nitrate cycle. Biproducts also include phosphates.
Rule 2: FEEDING FISH
Fish in the wild have an endless source of food. In your tank, what they receive daily comes from what you feed and what they can find in the tank. The more live rock the more natural foods exist. Offer them assorted foods. Some fish may not eat everything put in the tank. Different dealers use different foods so you may need to buy the fishes favorite food at the time you buy the fish. Have the shop owner feed the fish you want to buy. Even if they have been fed minutes before, if they are healthy they will eat more. If they don't eat - don't buy.
Things you can feed your fish.
Nori (sushi wrappers)
Fresh, live seaweeds
Brine - live and frozen
Mysid shrimp - live and frozen
Silversides - wild caught and aqua cultured - both frozen
Fish eggs - frozen
Clams, squid - frozen or fresh
There are other products too.
Rule 3: FEEDING CORALS
Feeding corals is not a necessity but they do much better when you do. They eat size specific food - large polyps eat large food like silversides. SPS corals like phytoplankton. Turn off circulation so that they can grab food and hold on to it.
Mushrooms.........................really don't need food
Brains,cynarinas,bubbles......krill,silversides (feed in early AM before lights come on is best)
Zooanthids, gorgonians........brine,cyclop-eeze
Frogspawns,hammers,
torches,elegance, plates......silversides
Ricordias............................brine, silversides
Acroporas,montiporas,sps....DT phytoplankton, cyclop-eeze
Colt,sinularia,leathers,
lemnalia,tunicates...............DT's, cyclop-eeze
Star polyps........................cyclop-eeze, or nothing
Rule 4: FEEDING ANEMONES
DO NOT FEED ANEMONES SALAD SHRIMP. They are cooked and it's like feeding them rubber. Offer them small amounts of krill, silversides, brine shrimp, clams or mysid shrimp. Feed 2 to 4 times per week. Should the anemone host a clown, the clown should feed the anemone. Do not overfeed.
Rule 5: FEEDING EELS
Eels can be difficult to start to eat. I have had an eel go 2 months before starting. They have poor eyesight so putting their food on a stick is best. Favorite eel foods include krill, large silversides, tiger prawns, squid, sand shrimp and sometimes fresh crab.
Rule 6: FEEDING LIVE FOOD EATERS
Lions and other fish that like live foods can be trained to eat frozen. It's much better and easier. Use the same foods as eels. Coaxing with food on a stick and making frozen look like it is alive is the trick. Fish learn from tank mates what is good to eat. You may have to start with live mysids, live sand shrimp or live goldfish/guppies but work hard to get them to eat frozen. Frozen guppies/goldfish can be used to transition from live foods.
Feeding Fish, Corals, and other creatures.