Beginner Topic 10 Saltwater Fish to Avoid for a Beginner Reef Aquarist

We gently offer some advice on which fish to avoid if you're stocking your first tank for the first time.
  1. Reef2Reef is here to help aquarists with all levels of experience. But we especially want to look after the beginners. Most beginners are chomping at the bit to fill their tanks with livestock. In reefkeeping, William Congreve's quote from 1693 is applicable: "Marry in haste, repent at leisure." In reefkeeping, if you do anything in haste, you will repent at leisure.

    Today, William Norman, an experienced reef aquarist, tells us his advice for choosing fish when you're a beginner.


    As a beginner it is best to stay away from fish with special needs in diet or environment and that may limit your long term plans. For example you might only have a fish only reef tank (FOWLR) today, but most of us graduate to wanting corals and there are some fish that view corals as tasty snacks.

    So here are my suggested 10 fish to avoid.

    10. Fish that get big. - Any fish that requires a larger tank than you currently have. I am a planner, so sometimes I will do something, knowing that it will work out in the end. But as a beginner, I would suggest you don’t acquire any fish that requires more space than you have. There are plenty of fish in the sea, so, don't force yourself into a poor decision later. Don't choose a fish based on how pretty it is in the book or at the LFS. Make sure you know what the adult size will be in an aquarium, which is often slightly different that the adult size in the wild.

    A scorpionfish, Rhinopias frondosa. They can attain the length of 9 inches.

    Photo is from the Reef2Reef archives courtesy of Lionfish Lair, ©2018, All Rights Reserved.

    9. Expensive fish - No matter how hard you try, mistakes will be made, accidents will happen and you will lose some fish. When you are starting out you will find this happens more often. It is devastating to lose any pets. It is worse knowing that you spent more that you should on a fish, and it died, sometimes quickly and/or unexpectedly.

    Here's a Wrought Iron Butterflyfish, guaranteed to set you back several thousand dollars.
    Photo is courtesy of NYAquatic, ©2018, All Rights Reserved.

    8. Any fish you haven't researched first. - It is very tempting to see a beautiful fish in the store or a web page and quickly pull out your wallet. Impulse buys are bad moves. I have been in many LFS listening to a salesperson talk a newbie into a fish they shouldn't have. Some fish have sworn enemies, some fish are very territorial, some fish are very hard to keep. You should know what is their diet, tank size as an adult, temperament, will they eat for certain, like invertebrates, corals or other fish. That is why you should do your research, build a stocking plan and ask for assistance in validating the plan against your goals.

    7. Damsels - While they come in lots of colors and are typically cheap, they can be monsters. These little fish will dominate the tank and can kill much larger fish. I had a friend warn me that the damsels he had would take bites out of his hand every time he tried to clean his tank. The only damsels that people tend to tolerate are ocellaris clownfish and are best when a pair are introduced together.

    6. Mandarin Goby/Dragonet - It is well documented that most mandarins die of starvation in captivity, but I included it on this list since they are super cool looking. If not already eating, they are hard to convert to frozen food or pellets or anything else. They require a large sustainable population of copepods and amphipods, which typically require a well established tank (one year or more) and little or no competition from other fish for its food. Mandarins are easily stressed and require ample space to hid and rest.

    5. Anthias - are sometimes referred to a jewels of the sea. Personally, they are one of my favorite schooling fish, but they can be hard to keep. Couple reasons. There are a few varieties with different personalities. Many shops miss label them, which can make this a harder exercise. They are grazers, so you need to feed them many small meals throughout the day, until they get use to your routine. Many new tanks will not be able to handle the additional bioload of this feeding activity. Also they do best in a harem. One strong male and quite a few females. This way any aggression gets spread out. (If the male dies one of the females will switch to male). Anthias are best left to larger tanks (120+) where they can have the space required for a large harem and a more experienced aquarist.

    A lyretail anthias.
    Photo is from the Reef2Reef archives, ©2018, All Rights Reserved.

    4. Pipefish - are a really cool and different-looking fish. I usually see children huddled around any tank that contains them. In the wild, they tend to live in grass fields with calm, shallow waters. Not surprisingly, people that do have success with pipefish typically need low flow and bright tanks with lots of live food. A word of caution: They may eat frozen food in a store and then refuse to eat anything when the environment changes. Aquarists who have had the best success keep them in a species-specific tank without any corals that have stinging tentacles/sweepers.

    A blue-striped pipefish.
    Photo is from the Reef2Reef archives, courtesy of Linda Cline, © 2018, All Rights Reserved.

    3. Wrasses - This selection is going to generate a lot of conversation. Yes, many wrasses are hardy and active fish. They flash color with lots of a personality. A great dual-purpose fish as they can help keep certain bad critters at bay in our tanks. They check off many of the criteria for beginners, but the downside is they can be aggressive to other fish--and to yourself. For every person I have spoken to, who has a model-citizen wrasse, there is another person who has a Tasmanian Devil. If you want a wrasse, I suggest putting it towards the bottom/end of your stocking plan. This will help more timid fish get established prior to the wrasses' introduction.

    2. Seahorses - So peaceful to watch, yet very hard to keep for reefers. Seahorses have very similar needs to pipefish, they actually do very well in a combined seahorse and pipefish tank without other fish. It is best to keep them in lower flow with grasses, lower temperatures (65F-70F) and require lots of water changes to keep their water clean.

    1. Tangs - Everyone loved Dory (powder blue tangs) and wants one in their tank. Unfortunately tangs are not an easy fish. They are highly susceptible to marine ich and parasites due to their thinner slime coat. When they get stressed (think the entire sale process) it becomes very likely they will come down with an issue. They also need room to swim. Some of the smaller ones will be fine in a 4ft tank, but most including Dories will need five (5) feet or more. If you have the room, add them last, as some can be aggressively territorial. Check a compatibility list, and make sure you research how to introduce these to your tank.

    The fish listed here are ones that are best left to more experienced aquarists. This is my list, and your list might be different. Remember, right now, most fish in the saltwater aquarium trade are still wild-caught. So, most fish have had a grueling trip to the LFS on their way to an aquarist's home tank. Don't take one of these home unless you can offer him or her the best possible conditions for a long and healthy life.

    Edit: It has been pointed out that "Dory" is a blue tang or regal or hippo tang, Paracanthurus hepatus, and not a powder blue tang, Acanthurus leucosternon, a close relative.

    Edit: A mistake was noticed with the temperature range for seahorses, and I've changed C to F. My apologies.


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    Author Profile: William Norman

    William Norman currently lives in South Florida. His love of the ocean was sparked by his father who was an oceanographer. Not wanting to be left on shore as a child, William quickly learned to swim, so he could accompany his father snorkeling and later diving on the reefs of Hawaii, where they lived. It is only the last two years that he has kept saltwater tanks. When he's not spending time learning about his reefing hobby, he enjoys traveling with his wife and two children, and being in/on/around the ocean.

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