Whilst the animnals we are likely to keep in a native marine reef are, by and large, very easy to feed. Some care does need to be taken.
Heres a brief list of the foods I have tried:
Frozen artemia (brineshrimp) is taken by just about everything, is easy to store and readily available for little cost. Perfect for 2 spot gobies, small mullet, prawns and beadlet anemones. Very small wrasse will probably ignore it if there is sufficient live food in the tank but as they grow larger they will supplement their diet happily with all manner of foods.
Frozen krill is less popular. Whilst most fish will take it. all too often they will spit it out again. Anemones are less fussy.
Frozen chopped cockles and mussels will be taken by mullet, but wrasse seem less than impressed.
Frozen whole mussel, in or out of the shell is enormously popular and provides a good meaty treat. The wrasse tear it apart and the smaller fish eagerly wait for scraps. Blennies will not hesitate to dive in for a bite.
Whole peeled prawns make a good mouthful for larger fish. My goldsinny is a voracious predator of prawns of all sizes and frozen peeled prawns are an easy substitute for live.
Mullet will graze on algae, especially hair algae.
So, they all feed eagerly on a range of foods. What care needs to be taken then? Well, ensuring that all fish get enough to eat is paramount. Feeding a whole mussel a minute before adding some frozen artemia ensures that the smaller fish all get something to eat while the larger ones are busy demolishing the mussel. I often add a peeled prawn or two with the artemia which keeps the goldsinny occupied. Variety is good. Try different foods, maybe at different times.
Live foods, if freshly caught are exxcellent. Occasionally I add a couple of hundred tiny prawns to the tank. The goldsinny goes crazy for them, the survivors of the initial frenzy are hunted in the weeks that follow, which keeps the goldsinny happily occupied. However, with a mass of rocks there are many hiding places and not all will get caught.
Its essential to observe the feeding closely, you need to be able to spot any problems early on to ensure the health of the animals. Species that are unable to compete at feeding time will need to be catered for or released. Adding live copepods, rotifers and phytoplankton may be necessary if small fish, fry or pipefish seem unable to browse effectively. If they seem to spend a lot of time searchinmg for food but rarely 'bite' then its likely that there is nothing to eat. There are a number of excellent online suppliers that sell the above foods. I use reefphyto.co.uk. and can reccommend their product and service.
Large blennies are particularly good at depriving other animals of food. Tompot Blennies are aggressive and greedy feeders and other fish will struggle to compete, occupy them with a large meaty morsal then add something for the others whilst its occupied.
If you keep filter feeders they will need an adequate supply of plankton. If you dont have any you'll need to add it regularly. All this may seem rather obvious - but its easy to let things slide and think that chucking in a regular feed will do - it wont! Observe feeding closely, give them variety and interest, and keep an eye out for those struggling to compete. If you cannot feed an animal correctly - and theres no shame in admitting it - let it go.