Aquatics Unlimited: Articles: Saltwater Aquarium Guide
Image 1
Image 2
Image 3

Saltwater Aquarium Guide (Green Sheets)

With the outstanding assortment of beautiful saltwater fish to choose from, it is no wonder that so many hobbyists dream of maintaining a marine aquarium. This guide is intended to answer many of the questions a novice marine aquarist may have, and to provide some basic guidelines for selecting and caring for saltwater fish and invertebrates. In addition, we hope that every saltwater hobbyist will read several good, current books on the subject. Please ask us for suggestions.

ClownWhat's the difference between saltwater and freshwater? Whereas freshwater fish are found in rivers, streams, ponds and lakes, saltwater fish are collected from oceans and seas. As such, their natural environment is quite stable and they do not readily adapt to major changes in water chemistry or temperature. In addition, since nearly all saltwater fish and invertebrates are captured in the wild (many freshwater fish are either tank or pond raised), there are greater risks associated with handling and shipping. The risks, shipping and collecting costs, and supply-and-demand also make saltwater specimens more expensive than their freshwater counterparts.

What equipment is needed? Most modern aquarium equipment is designed to be functional in either salt or fresh water, but it is important to select quality, reliable supplies. It hardly pays to save six dollars on a heater or ten dollars on a filter system and risk the loss of twenty or thirty dollar fish. Contrary to some opinions, undergravel filters are not essential in saltwater aquariums. Many of our customers have had success using the sort of equipment that we include in our "PRO" setups; deluxe heaters, outside power filters and airstones. The only necessary additions to a good freshwater setup are special gravel (crushed coral), sea salt mix, and a hydrometer.

Are saltwater fish hard to keep? Just as in freshwater, there are some species that are usually quite sturdy and some that challenge even the experts. The "Marine Care and Compatibility Table" portion of this guide is meant to help the hobbyist choose fish and invertebrates appropriate for his level of expertise. In addition, the individual specimen should be observed closely before purchase. Sometimes an individual or group of even the most hardy variety will have been subjected to just one too many changes, and will become weak or sickly or will refuse to eat. We will try to help in choosing healthy specimens as much as possible.

What size tank is needed? Almost any size aquarium can be used, but generally a larger tank will be easier to keep chemically balanced and has a lot more options when it comes to fish compatibility. On the other hand, assuming the household budget is a factor, it is better to set up a medium-sized tank with good equipment than to attempt a larger tank with inadequate equipment. Many of the most popular saltwater sizes are in the 30 to 55 gallon range.

Which fish get along? The Compatibility Table will help with selecting fish that are likely to get along. In addition, the three following rules will usually apply:

  1. Any fish that will fit into another fish's mouth usually ends up there.
  2. The less related any two fish are, the more likely they will get along.
  3. The less two fish resemble one another, the more likely they will get along.

Marine Care and Compatibility Table

  • a. PEACEFUL - not commonly known to bother other fish.
  • b. SPIRITED - normally peaceful, but may chase slow species.
  • c. MILDLY AGGRESSIVE - should not be kept with slow or timid species.
  • d. AGGRESSIVE - should be kept with larger, active fish.
  • e. TERRITORIAL - attempts to drive away fish of the same or related species and even unrelated fish with similar shape or colors.
  • f. PUGNACIOUS - not acceptable in community tanks.
  • g. VULNERABLE - likely to be harassed, picked on, or fin nipped by other fish, sometimes even by otherwise peaceful fish.
  • h. CHANGEABLE - may be mixed with other fish when young, but may become more aggressive when older, and may eat smaller fish.
  • i. HARDY - tolerant of various water conditions and not commonly affected by hard to treat diseases.
  • j. MODERATELY HARDY - a good specimen for a healthy aquarium.
  • k. TOUCHY - sensitive to water quality or disease prone.
  • l. SUBJECT TO "ICH" - particularly sensitive to this common but treatable parasite.
  • m. FAST GROWTH - may become much larger than purchased size.
  • n. HERBIVOROUS - need additional vegetable matter in the diet.
  • o. CARNIVOROUS - eats primarily "meaty" type foods, including brine shrimp, plankton or fish of suitable size.
  • p. EATS SESSILE INVERTEBRATES - feeds on or kills anemones, live corals, sponges, feather dusters or live rocks.
  • q. EATS MOTILE INVERTEBRATES - feeds on or kills shrimp, crabs or starfish.
  • r. SPECIAL FOOD - may require a special diet to remain healthy.
  • s. FILTER FEEDER - requires liquified foods.


annularis = b,e,k,n,p,r
bicolor = a,e,k,n
black or french = b,e,h,j,m,n,p
blue or queen = b,e,h,j,m,n,p
blue face = a,e,j,n,p
blue girdled = a,e,j,n,p
coral beauty = a,e,j,n
flagfin = a,e,k,n,p
flame = a,e,j,n
flameback = a,e,j,n
imperator = a,e,h,k,l,n,p
koran = b,e,j,n,p
lemon peel = a,e,k,n
passer's = d,e,h,i,n,p
potter's = a,e,j,n
regal = a,g,k,n,p,r
rock beauty = a,e,h,k,l,n,p,r
tibicen =a,e,j,n
yellow = a,e,j,n


common = a,g,i,m.o,q,r


purple queen = a,g,i,o
pink square = a,j,o


harlequin = a,i,o,q
royal gramma = a,e,i,o


orbicularis = b,e,g,h,i,m,p
pinnatus = a,e,g,j,k,p
teira = b,e,g,h,i,m,p


misc. = c,e,i,o
scooter = a,i,o,r


auruiga = a,e,j,o,p
black back = a,e,j,o,p
blue spot = a,e,k,o,p,r
blue stripe = a,e,j,o,p
copperband = a,e,k,o,p,r
punctato = a,e,j,o,p
falcula = a,e,j,o,p
foureye = a,e,j,o,p
fourspot = a,e,j,f,o,p
heniochus = a,e,g,j,o,p
latticed = a,e,j,o,p
longnose = a,e,j,o,p
melon = a,e,k,o,p,r
mertense = a,e,j,o,p
ornate = a,e,k,o,p,r
pakistan = a,e,k,o,p,r
pearlscale = a,e,j,o,p
pelewenses = a,e,j,o,p
racoon = a,e,j,o,p
saddleback = a,e,j,o,p
teardrop = a,e,j,o,p
triangle = a,e,k,o,p,r
vagabond = a,e,j,o,p
zoster = a,e,j,o,p


spotted = b,e,i,o


maroon = c,e,i
melanopus = c,e,i
percula = a,e,j
sebae = a,e,i
tomato = b,e,i


blue = b,e,i
green chromis = a,g,j
three spot = b,e,i
2,3, or 4 stripe = b,e,i
yellow = c,e,i
yellowtail blue = b,e,i


high hat = c,i,p
jack knife = a,g,j,p


asst. moray = b,h,i,o,q
ribbon = a,k,o,q,r,s?


fantail = b,j,o,p,r
orange spot = a,k,o,p,r


asst. = b,e,i,m,p,q


bar = a,e,i,o
catalina = a,j,o
clown = a,i,o
mandarin = a,e,j,o,r


asst. = d,e,h,i,m,o,q
sea betta = a,e,g,i,o,q


flame = b,e,i,o,q
longnose = a,e,j,o,q
spotted = b,e,i,o,q


asst. = a,h,i,o,p,q


dwarf = a,h,j,m,o,q,r
fu man chu = a,h,j,m,o,q,r
volitans = a,h,j,m,o,q,r

Moorish Idol

idol = a,g,k,o,p,r


bicolor = a,e,j,o,p,q


all = b,j,p,q


all = b,e,i,o


foxface = a,e,i,p


asst. = a,g,j,o,p,q,r
blue dot = a,g,k,o,p,q,r


all = a,g,k,o,r


leopard = d,h,j,,o,q,r
nurse = d,h,i,m,o,q,r


red emperor = c,e,h,i,m,o,q


spotted = b,e,h,k,m,o,q,r
striped = b,e,g,h,k,o,q,r


all = a,i,o,q


achilles = b,e,g,k,n,p
blue (Atl.) = c,e,h,i,m,n
blue (Pac.) = a,e,j,l,n
chevron = b,e,g,j,n
clown = b,e,g,j,n
convict = b,e,g,j,n
naso = a,e,g,j,n
powder blue = b,e,j,n
powder brown = b,e,j,n
sailfin = c,e,i,m,n
yellow eye = e,i.,n


clown = d,e,h,j,m,o,p,q
picasso = c,e,h,i,m,o,p,q
niger = c,e,h,i,m,o,p,q
undulated = f,h,i,m,o,p,q


bird = b,e,j,o
cleaner = a,e,k,r
coris = a,j,o
tusk = c,e,h,i,o



Atlantic = j,o,r,s
carpet = i,o,r,s
long tentacle = i,o,r,s
sebae = i,o,r,s
tube = i,o,q,r,s


hard = k,o,r,s
soft, = k,o,r,s


all = k,o,r,s


anemone = a,j,o,r,s
arrow = c,e,i,m,o,p,q
hermit = b,h,i,n,o,p,q
horseshoe = a,i,n,o
porcelain = a,j,o,r,s
lightfoot = b,h,i,n,o,p
spider = a,i,n,o,p

Feather Duster

all = a,g,j,r,s


all = a,j,o,r,s


Hawaiian = d,h,i,m,o,p,q
Indian Ocean = b,i,o,p,q


all = a,k,n,o,p,r


all = e,f,h,j,o,p,q,r

Sea Apple

all = a,i,n,p

Sea Fan

all = k,o,r,s


clam = a,j,r,s
scallop = a,g,j,r,s
cowrie = a,i,n,o,p


coral = b,e,h,i,m,o
camel = a,i,n,o
cleaner = a,i,n,o
fire = a,i,n,o
harlequin = a,j,q,r
mantis = e,f,i,o,q


all = a,g,j,r,s


African = a,i,o,p
blue = a,k,o,p
brittle = a,i,o,s
chocolate chip = a,i,o,p
serpent = a,i,o,s


all = a,j,n,o,p

The information in this guide is based on aquarium literature, personal experience and customer feedback. Exceptions are always possible, but these guidelines should give a basic understanding of the normal behavior of aquarium specimens. Many factors, including tank size, water quality, available hiding places, and even the order in which specimens are added, can affect compatibility.

Fish and Invertebrates Together?

Many hobbyists desire to keep a mixed collection - with both fish and invertebrates in the same aquarium. While such a display can certainly be very beautiful (especially with symbiotic species like anemones and clown fish), there can be problems involved. The most effective treatments for saltwater "ich" also kill invertebrates. Apparently, the cell structures are similar enough between parasites and invertebrates that the reactions to chemicals are quite the same.

Since the treatment/removal time for "ich" medications is at least four weeks (please see "Treating Saltwater Ich" treatment information elsewhere in these pages), the unfortunate hobbyist is often forced to sacrifice either the invertebrates by moving them to another tank (if one is available) or the fish by risking ineffective treatment.

To further complicate matters, salt water invetebrates are suspected of being "carriers" of "ich", and since a suitable treatment has yet to be utilized, suppliers cannot guarantee that invertebrates are free of these parasites.

The novice saltwater hobbyist is advised to weigh the risks of the mixed collection against the obvious benefits and to make plans accordingly. Freshwater dips and quarantine tanks can reduce the chances of newly acquired specimens introducing disease to an established aquarium. Low fish population density (few fish in a large tank as in the currently popular "reef" type aquariums) may reduce epidemic outbreaks and allow fish to deal with parasites in their natural manner.

It is hoped that new advances in disease treatment and a better understanding of parasite control will lead to a higher degree of success with mixed collections.

Copyright © 1996 Aquatics Unlimited
All rights reserved.

Aquatics Unlimited | 3550 S. 108th Street | Greenfield, WI 53228
Monday-Saturday 10:00 a.m. - 9:00 p.m., Sunday 10:00 a.m. - 6:00 p.m. | Phone: 414-543-2552 | Fax: 414-543-4929