What should I feed my tropical fish?

Author: Adrienne Dodge

First published in Aquarium World August 2013

This is a question that commonly pops up.  What you feed your fish is as important as the aquarium conditions you provide for them. For newer fish keepers I have placed a table at the bottom of this article giving some idea of the basic foods to feed the type of fish typically kept by beginners to the hobby.

The type of food you feed your fish depends largely on the following   

- The size of your fish and the size of its mouth                                                                                                                                                      

- Whether your fish is a herbivore (eats plants), a carnivore (eats animals), or an omnivore (eats both)                                                              

- Is your fish a surface feeder or a bottom feeder?                                                                                                                                          

- Does your fish feed during the day or at night only?     

It is important to remember that regardless of what type of food you feed to your fish, varying the diet to ensure balanced nutrition is also necessary. There are a huge number of commercially prepared fish foods available that can be used. A lot will depend on your preference and how convenient it is for you to feed it. A combination of dry as well as frozen and fresh/live foods will ensure a well-balanced diet.       

Dry foods come as pellets, flakes, wafers and sticks. Formulations for herbivores, omnivores and carnivores are easily obtainable in your local fish/pet shops (LFS), as is fish specific food ie food for bettas, goldfish, cichlids, arowana. Most foods available range in size from tiny pellets for fish with small mouths, to large sticks for the bigger predatory fish like Oscars or Jaguar Cichlids.

Each food type has its pros and cons – sinking wafers are great for catfish but no good for surface feeders ie Hatchet fish, Pantadon Butterfly Fish. Flakes can be crushed or crumbled for smaller fish like Guppies and Neon Tetras but will not sustain large bodied fish as they do not contain enough bulk. Likewise large pellets are too big for fish with tiny mouths such as Mosquito Rasbora, or narrow throats such as the Rainbowfish species. Some pellets will float for a while before slowly sinking, often making these the preferred food for a community tank.

The majority of frozen or freeze dried foods are processed organisms like brine shrimp or bloodworms. Some people believe that freeze-drying food retains more vitamins than freezing but both result in some loss of nutrition. Most fish prefer frozen foods over freeze-dried but freeze-dried are more easily crumbled for smaller fish. Commonly available freeze-dried foods found in NZ are tubifex, bloodworms, daphnia and de-capsulated brine shrimp. Brine shrimp, bloodworms, daphnia and mysis shrimp are some of the frozen foods available from your LFS.

Most fish enjoy live foods. Foods like microworms, whiteworms and blackworms are easily cultured at home. Daphnia can be found in water troughs and ponds exposed to the sun while mosquito lavae can easily be cultured by leaving a bucket of water, with a handful of grass added, out for the mosquitoes to lay their eggs in.  Larger predators will also enjoy worms and crickets. More experienced fish keepers and breeders also hatch bbs (baby brine shrimp) for feeding to their newly hatched fry or grow-out tanks.

Beginning fish keepers – the majority of new fish keepers tend to start off by purchasing fish such as guppies, neons, and the danio species (all small tropical fish), or mountain minnows (coldwater fish). Another fish, which is popular with new fish keepers is the dwarf gourami. Bristlenose catfish and corydora (cory) are also fish commonly purchased by new fishkeepers.  You will note that there are blanched vegetables listed below for some fish – vege clips can be purchased from LFS, for around $11, to hold these and prevent them from floating around the tank.

Goldfish are a cold water fish which new fish keepers often purchase.  The type of goldfish you buy largely determines what sort of food you should feed it, as does whether or not it is to be kept in a pond or a tank.  I will just cover food for a goldfish in a tank.

If you have a goldfish like a Comet or a Shubunkin, which are the original shaped goldfish, then a high quality flake or sinking pellet food will be good for them.  Lower quality will cloud your tank water quickly.  However if you purchase a fish like a Blackmoor, Oranda, or any fancy goldfish for that matter, you are better to feed them a sinking pellet food.  The reason for this is that the swim bladder in fancy goldfish is packed in tightly and when they come up to eat flake foods it is common for them to suck in air while eating.  The location of the swim bladder makes it very difficult for this air to be released.

“In terms of fish food, variety truly is the spice of life. Just keep it fresh and feed it lightly." ~Ted Dengler Coletti

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