FAQ: Beginning Saltwater -- Buying Your Fish

Beginner Saltwater Fish

Contributed by Mark Rosenstein and Tom Sasala

It is easy to make mistakes when setting up your first saltwater tank. Both for the sake of the fish and your wallet, start with only a few hardy inexpensive fish. Most marine fish are collected in the wild rather than captive raised, so your mistakes impact the world's oceans!


The best beginner fish for a marine tank are damsels. These fish are very hardy, being able to withstand worse water conditions than most other marine fish, they are not picky eaters, and they are fairly inexpensive. The down-side is that they are fairly aggressive. One or two will co-exist in a tank. There will be a lot of fighting if you put more in. Dealers get away with a lot in their tanks by keeping the tanks so crowded that none of the fish can establish a territory. This is not acceptable for long periods of time. It is best to use damsels to break in a new tank. If you are then going to add other aggressive fish, you can keep the damsels. If you want to keep shy or delicate fish, you should take the damsels back to the pet store once you and your tank are ready for more fish.

Some damsels, such as the blue damsel and yellow tailed damsels, are not as aggressive as others, such as the three striped and domino damsels. In any case, damsels are certainly the best fish to start with.


Some people like to break in a tank with mollies which have been acclimated to salt water. This gives you the benefit of starting with inexpensive fish and get used to maintaining salinity and pH on not-so-sensitive fish. Although safer, you don't achieve much marine experience this way. Mollies are captive raised and bred.

If you buy mollies for your saltwater tank, you can acclimate them by dripping saltwater into the bag over a period of 6-8 hours, removing some water when the bag gets too full. Slowly increasing the salinity gives the mollies time to get used to their new environment. You can keep the mollies in the tank after it cycles, but any aggressive fish with continually harass the passive mollies.


Clownfish are related to damsels, and are fairly hardy. However, they are more difficult to acclimate to a new tank. Clowns, in general, are very territorial, but are not otherwise aggressive except to other clowns. They will do fine without an anemone, which is good since anemones are much more difficult to keep. Anemones require very clean water and high quality lighting. Also, each species of clown likes particular species of anemones, and none of them will regularly inhabit the inexpensive and easier to maintain Caribbean anemones. Some clowns are captive raised.


These small fish are somewhat hardy and are unlikely to cause trouble for the other fish in your tank. Some of them show a lot of personality, though they will get lost in a large tank. Many of these fish are excellent additions to a tank to help control algae. However, some feed by sifting through the substrate and will be very hard to keep fed in a fish-only tank (e.g., the mandarin fish).

Tangs (Surgeonfish)

Tangs are fairly hardy, though they are very susceptible to marine ich. Being algae eaters, they are useful to introduce when your tank starts growing algae. They must be fed leafy greens if there is no suitable algae growing in the tank (green algae). Many different tangs are commonly seen for reasonable prices.


If you are setting up a tank for large aggressive fish, you can start with triggers and/or lionfish, as they are hardy. However, mistakes with them can be very costly, so you may want to practice on less expensive and easier fish. Also, carnivorous fish such as triggers and lions should be fed plenty of shell fish and other marine life. Specifically, many people feed lions feeder goldfish. This is really a bad practice because goldfish are freshwater fish and do not provide the same nutrition that a saltwater fish would. Specifically, feeding saltwater fish freshwater food can cause premature liver failure and the early demise of your fish.

Angels and Butterflies

These are fish that must be ignored while in the pet store - all are both delicate and difficult fish to keep. Many butterflies have specialized diets which make them hard to maintain in captivity.

Batfish are also other fish that should be avoided.


Other saltwater fish which can be attempted once you get good at controlling the fish's environment are hawkfishes, grammas, dottybacks, basslets, and wrasses. Some are more difficult to keep than others, but not nearly as difficult as angles and butterflies.

Fishes to Stay Away From

All angelfish, all butterflyfish, Pipefish, Seahorses, Long-nosed Filefish, Blue Ribbon Eels, Stonefish, and Moorish Idols. Mandarin fish should also be avoided in non-reef tanks (they are hard to feed).

Beginner Invertebrates

Many people believe that invertebrates are only for mini or micro-reef tanks. Not so. There are quite a few invertebrates that do well in non-reef tanks. However, not a lot of invertebrates should be attempted by inexperienced saltwater fish keepers. Below is a brief summary of the more hardy invertebrates available to aquarists.


There are many different shrimps available on the market, with most of them being perfectly suitable for a lightly loaded saltwater tank. In fact, some shrimps are more suitable for fish and invertebrate tanks than for a reef tank since they like to eat corals.

Some of the more popular shrimps are Cleaner shrimp Lysmata amboinensis, Blood shrimp Lysmata debelius, Candycane or Peppermint shrimp Periclimenes brevcarpalis, and Coral Banded shrimp Stenopus hispidus. The cleaner shrimp is denoted by a white on red stripe down the middle of its back. They are fairly inexpensive and easy to keep. They should, however, be kept in small groups (3-4), as this makes them more social and more likely to come out often. The Blood shrimp is intensely red with some white spots. It is a very striking animal, but usually commands a high price. The Coral Banded shrimp is very popular with reef keepers, but must be watched around small fish. This shrimp has been known to eat small fish without thinking twice.

Most shrimps are scavengers and don't necessarily need to be fed overtly (they usually eat food dropped by fish). If your fish your fish consume most of the food before it makes it to the bottom of the tank, then some extra food should be given to the shrimps after the fishes have been fed, or at night (most shrimps are nocturnal). Shrimps readily accept most frozen foods and dried foods (brine shrimp, flake food, etc.).

Stay away from Harlequin shrimps Hymenocera sp. as starfish are their only source of food.


There are many different type of crabs, but the most commonly seen varieties are anemone crabs Neopetrolisthes ohshimia, arrow crabs Stenorhynchus seticornis, and hermit crabs Dardanus megistos. Anemone crabs live in anemones, as do clownfish (e.g., Sebae), and vary greatly in color and shape. They are usually acquired indirectly by buying an anemone, but are some times sold separately. These crabs should have a host anemone to feel comfortable. Arrow crabs are very interesting animals which should be kept one to a tank, as they will continually fight. Also, Arrow crabs should not be kept with Coral Banded Shrimps as they will fight as well. Hermit crabs are also interesting, and vary in color and size. Most are passive, butsome will eat corals and other invertebrates.

Crabs are generally omnivorous and readily accept the same foods as your fish. Like shrimp, crabs can only eat food which has made it to the bottom of the tank. Thus, ensure some food is in reach of your crabs.

Sea Urchins and Starfishes

Most sea urchins and Starfishes are suitable for beginners who have a few months experience. Once again they vary greatly in size, shape, and color. Beware, some sea urchins are poisonous. Most sea urchins and starfish feed on detritus and algae, and small particles of food that have fallen within their reach.


Simply put, amemones should not be kept by beginners (sorry folks). They all require very strong lighting and excellent water conditions. Do not believe a fish store guy that tells you otherwise. Unless you are willing to invest a lot of money in proper lighting, do not try to keep an anemone.

Some Notes on Invertebrates

Invertebrates are very sensitive to water quality. Signs of stress due to poor water quality will usually be exhibited first by invertebrates. Therefore, shrimps, anemones and other invertebrates should never be used to cycle a tank. Moreover, you should never add an invertebrate to a diseased tank or a tank which does not have stable water quality parameters (e.g., pH, temperature, etc.).

Other points to note. Shrimps need iodine to properly molt, as well as calcium . If you do not change water regularly (which you should), or if you do not feed live or frozen food frequently, then you may need to supplement your water with iodine. Without proper levels of iodine, shrimps will not molt properly and will most likely die. Also, copper kills invertebrates at much lower concentrations than fish. If you have ever used copper in your tank, DO NOT put invertebrates into the tank. You will never be able to adequately remove all the copper such that you can keep invertebrates alive and happy. Finally, crabs usually outgrow their shell sooner or later. Therefore, you will need to provide a new larger shell (they usually try a few out before sticking with one, so you will probably need at least a couple).

Invertebrates to Stay Away From

Tridacna clams (they need strong lighting), Flame scallops (they are nearly impossible to feed in an aquarium as they are filter feeders), Octopi (they have very short life spans), Nudibranchs (they are difficult/impossible to feed), any hard or soft coral (they need very strong lighting), and sea squirts (they can release poisonous toxins into the water).

Selecting a Saltwater Fish

Since saltwater fish are usually more expensive than freshwater fish, you have a great stake in getting them home alive and keeping them alive for the long term. You must realize that most fish you see in stores were swimming around the vast ocean a mere week ago. As such, the stress of capture and transportation can wreak havoc with the biological processes of the animal.

The most important thing when buying a fish is to not be overcome by the buying impulse. Before buying any animal, you should ask `Can I keep it happy'. Merely keeping the fish or invertebrate alive doesn't mean it is happy. Fifty goldfish may live in a 10 gallon tank, but they certainly won't be happy or healthy. Buying a fish you know nothing about and then asking if you can keep this fish happy is a very bad practice. Also, as hard as it is to say this, don't feel like you are doing a sick fish any favors by taking it home. If you have the room and time to nurture the sick fish, then I suggest you help out the environment and care for the sick fish rather than letting it die. However, if you are just going to place the fish into your main tank because you don't have the time or inclination to set a up a quarantine tank, then don't bother. It will only result in the death of the fish and the lightening of your wallet.

Once you decide on a particular fish, don't be afraid to ask the store to hold it for you. A good store will always hold a fish for you (don't patronize stores that won't!). Also, ask to see the fish eat. If the fish is healthy and eating, then it most likely is a good specimen. Finally, check the fish closely for spots, irregular patches, missing scales, and wounds. Torn fins will usually heal and are not much of a problem.

Bringing the Fish Home

Once you get the fish home you should set the bag in the destination tank, thus allowing the temperature to equalize. After about a half hour or so, add a 1/4 cup of tank water to the bag. Repeat this process once every 15 minutes for an hour, removing any water if the bag gets too full. Any water you remove from the bag should be disposed of. It will most likely contain parasites and other bad things.

After you have the fish acclimated to your tank's water chemistry, there are a couple of things you can do. You can place the fish directly into the main tank and hope for the best, you can give the fish a freshwater dip and then place it into the tank, or you could place the fish into a quarantine tank.

The best scenario is to give the fish a freshwater dip and place it into a quarantine tank. Keep the fish in the quarantine tank for 2 weeks and watch for signs of disease. If the fish gets sick, you can medicate the quarantine tank without affecting the chemistry of the main tank. If you are going to quarantine the fish, you should acclimate the fish to the quarantine tank's chemistry, not the main tank.

If you don't use a quarantine tank, then it is a very good idea to give the fish a freshwater bath before placing it into your main tank. The freshwater bath will cause any parasites attached onto the fish to let go and remain in the freshwater (to die a lonely death). Otherwise, parasites left to their own will reproduce very rapidly in captivity and usually infect all the fish in the tank.

To give a marine fish a freshwater dip, prepare a container of dechlorinated freshwater with a similar chemistry of the destination tank. That is, make sure the pH and temperature are as close as possible to the destination tank (this is critical!) . Remove the fish from the bag and place the fish into the container for 3 to 5 minutes. Watch the fish closely for signs of stress. If the fish stops moving or begins to float, remove it immediately and place it in the destination tank (either the main or quarantine tank).

In placing the fish into the freshwater bath, never pour the fish into the container. Use a tupperware container or a net to capture the fish and place it into the dip. The store water should never be introduced to the freshwater bath, or any of your tanks. This water usually contains all sorts of nasty diseases and organisms.

If you put the fish into the main tank and it comes down with an illness, it should be removed to a quarantine tank immediately. Do not risk spreading the illness to the other fish in the tank (although it may already be too late).

Some more information on setting up a quarantine tank can be found in the Archive.

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