The best gift here is probably a 10 gallon aquarium kit.  These usually come with everything required (though they often lack a heater) and are much better value for money than buying everything new separately.  Ten gallons is large enough to have a decent choice of species, yet small enough to keep costs down and be easy to find space for.   Five gallon kits are cheaper but they are much more restricted in terms of what you can keep in them.  If you have the money, 20 gallon kits allow a wider choice of species and decor, as well as increased stability in tank conditions which may make fishkeeping a little easier.

If you are short of money, check the web for second hand equipment.  Be careful to look over what you are buying carefully.  Remember that because it’s second hand, some of it may well be mismatched, missing or not work.  You may well end up buying the problem items new and this can raise the costs above what you initially estimated.  Been there, done that.  Even so, it can still be a lot cheaper than buying new.

Many people buy plastic kits that are cheaper than glass.  These are not such a good idea for a couple of reasons.  Most of these kits lack lighting, they scratch more easily and so don’t last as well, they don’t come with heaters, many heaters aren’t safe for use in them, and they may also lack a filter.  Many of them are also too small for anything other than a Betta or some shrimp.  If your budget is limited, I recommend second hand glass aquaria over these.

Another excellent gift is a book on aquarium keeping.  There’s a lot to aquarium keeping and having a decent book constantly on hand is a good way to prevent mishaps and respond to emergencies.

If the person you are buying for isn’t yet ready for fish, or isn’t sure that an aquarium is right for them, a book can give them a good idea of whether it is what they really want, and what type of aquarium would be best for them.

Don’ts when buying for new fishkeepers:

-Don’t buy the fish at the same time as the tank.  Get them after the aquarium has been set up for two weeks with plants in it, or fully cycled by another method.

-Don’t buy a goldfish bowl for a goldfish.  Goldfish bowls are far too small for a large, waste-producing fish like a goldfish.

-Don’t buy live animals immediately before Christmas.  The stores will be insanely busy and the salespeople won’t have time to help you as much as they normally would.  In bad cases, the animals may also not be as well looked after because the staff get overwhelmed.  Buy the tank, then go back and buy fish once the tank is set up and cycled.

-Don’t buy any pet you aren’t sure they want.

Here are some suggestions for groups of fishes that are compatible inhabitants for 5 gallon tanks.  I have only included fish is that are at least relatively easy to keep.

Note: I am assuming a standard 5 gallon long tank. If your 5 gallon tank is tall and narrow, it will support fewer fish as it is surface area that determines the number of fish you can have. There are a variety of rules of thumb people use for determining number of fish. For a properly-filtered tank of standard proportions containing tropical species, a 5 gallon tank should contain no more than 10 inches of fish. I have kept the fish inches here to 8.5 or less because this leaves more room for equipment malfunction such as short power outages and human error.

Cold water fish need more space – no more than one inch of fish per gallon in a standard-sized tank.

The tanks:
5 gallon tank with plants and a pH of between 6 to 7.

Fish Tank One: Amazon Nano Aquarium 1
6 Neon Tetras
1 Otocinclus

Fish Tank Two: Amazon Nano Aquarium 2
6 Black Phantom Tetras

Fish Tank Three: Betta Bachelor Pad
1 male Betta

Fish Tank Four: Lady Betta and Frogs
1 female betta
2 dwarf frogs
1 Otocinclus

5 gallon tank with a pH of 6.5 to 7.5

Fish Tank Five: Subtropical Stream
4-5 White Cloud Mountain Minnows

Fish Tank Six: Mini Catfish Tank
6 Pygmy Corydoras
1 Otocinlus

5 gallon tank with plants and a pH of 7.0  to 7.6

Fish Tank Seven: Where’s the Fish?
8 shrimp of any mix of species that doesn’t exceed one inch, Cherry shrimp is a good beginner species
1 horned nerite snail

Fish Tank Eight: Guppies, Guppies, Guppies
5 Male Guppies
1 horned nerite snail

Because they come from running water, they require well-aerated water. This means they should have a filter or at least an air stone, and may well enjoy filtration that produces a strong current.

Crayfish are good at escaping, and tanks for them should have a tight-fitting lid that they cannot get out of.  They typically get to the top of the tank by climbing up any equipment that extends to the top of or out of the tank. Hiding places are important in order to make the crayfish feel secure, and there should be more hiding places than crayfish in a given tank in order to reduce fighting.  Crayfish like to burrow and will rearrange tank decorations if the decorations are light enough. They also eats live plants, so try not to get too attached to any decorating scheme or plant you put in their aquarium.

They are are best kept one to a tank, as they are likely to fight with each other. Some may also be kept in male-female pairs, which is necessary if you want to breed them.  There are also a couple of very small species in the genus Cambarellus that can be kept in groups if sufficient hiding places are given. Like Bettas, crayfish are sometimes used in animal behavior labs to demonstrate aggressive behavior – in both species the animals cannot actually get at each other.  The behaviors are observed as they threaten each other through the glass.

Crayfish are larger than most other invertebrates commonly kept in aquaria and large adults will need considerable space.  Ten gallons is enough for an adult of most of the North American species, but some of the Australian species can reach 16 inches and would need a 30 gallon or larger tank. There are a few dwarf species such as the Dwarf Cajun Crayfish, and Mexican Orange Dwarf Crayfish, that can be kept in a smaller fish tank or in a group in a 10 gallon tank if there are enough hiding places.

Crayfish will eat fish if the fish are small enough, so tank mates need to be considered very carefully.  Slow-moving species of fish are likely to get their fins damaged even if they do not get caught. The dwarf crayfish species can be kept with fish, but keeping them with very tiny fish or fry is probably not safe, and they should not be kept with large fish because the fish may eat them.

Crayfish can be fed on shrimp pellets or flakes, but there are often specialty crayfish foods available and many crayfish enjoy vegetables such as zucchini or peas.  If you live in a soft water area, you may wish to add calcium to their water, as this nutrient is important for growing a healthy exoskeleton.  Molting crayfish will eat their discarded exoskeleton to recover the nutrients, so this is often left in the tank.  Temperature requirements vary, but many species are happier in cooler water than the standard tropical tank.

Some Interesting Crayfish Species:

Procambarus alleni “electric blue”, Florida blue lobster
6-8 in, typical needs for a crayfish.

Procambarus sp. “Marble”
This species has no males.  The offspring are clones of the parent. More mundanely, it grows to about 4 inches in length and has typical requirements.

Cambarellus patzcuarensis Mexican orange dwarf crayfish
Thi species is tiny, at 1 to 1 1/2 inches in length.  If it can be kept was small fish, but not with large fish as the fish may eat this crayfish.  Many individuals can be kept in the 10 gallon tank so long as there are hiding places. It can stand warmer water, being comfortable in 60-82F.

Cambarellus schufeldtii Dwarf Cajun Crayfish
Very similar to the Mexican Orange Dwarf.

Cherax tenuimanus “Blue Marron”
This species grows large at 10 to 16 inches in length and requires a larger tank of 20 to 30 gallons.  It likes temperatures of 60 to 72 Fahrenheit, and care is otherwise as for most crayfish.

Sources:

Aquatic Community Aquarium Forum

canadiancrayfish.ca

McClure, Susan. Crayfish Care. Badman’s Tropical Fish.

Problems With Betta Bowls

However, the waters from which they come are warm: the average temperature is 24-30C (75-86F), according to Fishbase.org. This is much higher than the temperature in most people’s houses, especially in the winter. While they will survive in an unheated bowl provided the room is decently warm, housing them like this seems questionable. When kept at lower temperatures, Bettas are less active and are more susceptible to disease.

While Bettas do much better than most fish in low-oxygen conditions, they still suffer from build up of fish wastes when kept in small bowls. Such bowls must be cleaned much more frequently than a tank to prevent build-up: 100% water changes multiple times per week. The long fins of male bettas are susceptible to finrot, and dirty water increases the likelihood of problems.

Some of the objects in which Bettas are kept are too small for any fish. In petstores, they are often kept in hand-size bowls, or worse, in plastic drinking cups. I’ve even seen a few in containers narrower than their body was long, not counting the fins. Moral sentiment and the fish’s health aside, this is not a sensible way to sell these fish, as they cannot display properly and their beauty is completely invisible.

Advantages of a Heated Aquarium

Keeping these fish in an adequate-sized and warm tank has advantages to the fishkeeper in addition to feeling good about the way you keep your fish. Healthy fish display more, build bubble nests and check every nook and cranny of the aquarium for missed food. They are much more interesting to watch, and a betta doing an aggressive display in a well-lighted aquarium is a truly stunning sight.

Sources:

Fishbase.org

RandomWiktor. Tiny Mud Puddles and Other Lies: Myths and Misconceptions About Our Beloved Bettas

One: Not do research. When I was first starting out, most of my problems stemmed from this.

Two: Not do regular partial water changes. Because I hadn’t done number one, I didn’t realize that I was supposed to do this, or how one should do this.

Three: Put too many fish in the aquarium. This compounded problem two.

Four: Assume fish are short lived. A few fish, like annual killifishes, live only a few months in nature but a Corydoras catfish can live for up to seven years in captivity and a goldfish can reach 20 years of age. If you make this wrong assumption, you may not notice you are doing something wrong.

Five: Buy one of each species. Many fishes are schooling and do not do as well without the company of their own kind.

Six: Keep goldfish in a goldfish bowl. Common goldfish can grow up to 12 inches in length and produce large amounts of waste. They do not belong in goldfish bowls.

Seven: Started with too small a fish tank. A five gallon tank makes a perfectly good aquarium, but water parameters can change quickly and you can’t keep many fish in there.

Eight: Not feed bottom feeders sinking food and depend on one brand of flake food for everything. Corydoras catfish get hungry and don’t feed off the surface. Fish benefit from a varied diet just as we do.

Nine: Keeping a Betta in a community tank without a plan B or enough hiding places for fish to get away. It killed one of my Neon Tetras, so we put the Betta in a breeding trap that wasn’t really big enough for it.

Ten: Put a Pygmy Gourami in with Cherry Shrimp. Pygmy Gouramis may have small mouths, but they regard shrimp as food and that one fish harassed the shrimp unmercifully. If it hadn’t been for the extremely thick live plants I think I would probably have lost all my Cherry Shrimp.

The last one wasn’t all that long ago, so such mistakes aren’t limited to beginners. No matter how much you think you know, do your research! And if you possibly can, keep a spare tank for quarentine, hospital use and unexpected animosities.

Freshwater Shrimp

Freshwater shrimp are probably the most decorative freshwater invertebrates.  There are many species, each with its own color pattern and mode of life.  As most species are small, they do not require much space. Freshwater shrimp are harassed or eaten by many fish species so tank mates must be considered carefully.  I tried keeping Cherry Shrimp with a Pygmy Gourami and regretted the decision. The Gourami harassed my shrimp and probably caused the death of two of the five.   Endler’s Livebearers, however, coexisted peacefully with the shrimp.

Different species have different temperature and pH tolerances, but some of them, like the Amano shrimp, tolerate cool water very well.  The Amano shrimp requires brackish water to breed, which makes it very difficult to breed in captivity.  Individuals in pet shops can be assumed to be wild caught.   Red Cherry shrimp prefer tropical temperatures but have a tolerance for a wide pH Range and can be easily bred in captivity.   They are easy to find and are recommended for beginners.

There are so many different species of freshwater shrimp with so many different needs that it is hard to make generalizations.  Detailed information on the different species of shrimp and their care can be found at http://shrimpfanatics.com/.

Crayfish

Crayfish live in running water in nature.   This means they need a filter or at least an air stone.  They are are best kept one to a tank as they are likely to fight with each other.   Crayfish are larger than most of the other invertebrates we are discussing here and large adults will need considerable space.  Ten gallons is enough for an adult of most of the North American species, but some of the Australian species can reach 16 inches and would need a 30-50 gallon tank.  There are a few dwarf species such as the Dwarf Cajun Crayfish, Cambarellus schufeldtii, that can be kept in a smaller tank or in a group in a 10 gallon tank if there are enough hiding places.

Crayfish will eat fish if the fish are small enough, so tank mates need to be considered very carefully.  Crayfish can be fed on shrimp pellets, but there are often specialty crayfish foods available.  Temperature requirements vary, but many species are happier in cold water than a tropical tank.  More information can be found at canadiancrayfish.com.

Triops

There are two Triops species commonly kept in captivity, T. cancriformis and T. longicaudatus.  Both have similar care requirements.  Triops prefer warm water of about 22-31° C.  They do not require much space.  One Triops can easily be kept in a gallon container.   They are typically bought as dried eggs which are sent through the mail without harm.  The eggs must dry out, otherwise they will not hatch.  They prefer a neutral to alkaline pH.   A filter is not required, but they produce enough waste that a weekly 25% water change is recommended if you aren’t using a filter.  They will eat almost anything.  More information about Triops can be found at mytriops.com

Snails

While people often try to get rid of snails in their aquarium, snails can be a fascinating addition if you get the right species.  Any animal can be a pest if it’s in the wrong place.

Snails do not eat fish poop.   They usually eat uneaten fishfood, algae, and some aquarium plants.   The last is the reason why they are often unwelcome in planted fish tanks.  Snails require a certain amount of calcium in the water to build their shells, and for this reason tend to do better in hard alkaline water than in very soft acidic water.

Apple snails grow large and eat plants.  They are sold under a variety of names, including Golden Mystery Snail, Ivory Snail, Mystery Snail, and Giant Ramshorn.   There are multiple species, one of which, Pomacea maculata, is the world’s largest freshwater snail.  It can grow up to a diameter of 6 inches.  Because of its size it is not really suitable for bowls or small tanks.  More information on apple snails can be found at applesnail.net.

Malaysian trumpet snails burrow in the gravel and eat uneaten fishfood.   They do not eat plants.  They have an unusual elongated shell that makes them easy to recognize.  More information can be found at planet inverts.

Common pond snails are the snails that turn up unintentionally when you buy aquatic plants.   They breed prolifically, and are often considered a pest.  I currently have a couple in my aquarium and they appear to be doing no harm, but that may be because the plants in my tank are things like java fern which are avoided by most plant eaters.  The pH is low enough that it may be inhibiting them as well.  These snails are easy to feed, do well at both tropical and low temperatures and are not aggressive towards other animals so in the right place they can be good tank inhabitants.

There are a number of snail species around in addition to those above.  Knowing the habits of the species you pick will go a long way to making you happy with your snails.

In the End

There are many interesting invertebrates that can be kept in freshwater tanks.  Each type of invertebrates has its own needs and habits which should think consider as you would for any fish that you decided to add to your tank.  When treated with respect, freshwater invertebrates can be great tank inhabitants.

Goldfish, Carassius auratus: Superb in Large Unheated Aquariums

Goldfish grow.  Common goldfish can grow up to approximately 12 inches in length which is larger than some of the containers the juveniles are kept in.  They also produce a good deal of waste as they grow.   Fancy varieties usually stay smaller than common goldfish, but their fancy fins are inclined to develop finrot in dirty water.  This makes the lack of a filter problematic.  Goldfish are cold water fish so the lack of a heater is perfectly fine.

In short, they are ideal for a large unheated aquarium with filtration but are not suitable for a bowl.

White Cloud Mountain Minnow, Tanichthys albonubes: Good for Small Unheated Aquariums and Large Bowls

White cloud mountain minnows prefer lower temperatures than most tropical fish and for this reason they are often kept in unheated aquaria.   Their natural temperatures are 64-71F.  They are very small fish, staying under two inches in length.  However, they do school so is important to provide enough space for at least a couple of fish, preferably more. Fortunately their small size means that two or three can be kept comfortably in a 2 or 3 gallon aquarium. Of all the fish discussed here, these are probably the best for a large unheated bowl or small unheated aquarium.

Zebra Danio, Brachydanio rerio: Not Ideal

Most danios are small, the zebra danio being 1¾ inches in length, and they are tolerant of a wide range of temperatures.  Their natural temperature range is 64-75F.  However, they are fast swimmers and like to school which makes keeping them in a tiny aquarium questionable.

Watching a school of these fish in a large tank is a completely different experience from watching one or two in a tiny tank.  In a large tank they can get up speed and they seem to fly through the water in a group.  It is beautiful, but it is something you will never see if you put these fish in a betta cube.

Betta, Betta splendens: Ideal for Small Heated Aquariums or Bowls

Bettas stay small, usually growing to approximately 3 inches in length.   The waters from which they come are naturally rather stagnant and they have the ability to take in oxygen from the air.  This greatly increases their resistance to foul water.  They dislike fast filtration.  They are solitary in temperament and swim slowly.  This makes them seem like an ideal candidate for the small unfiltered bowl.

However, the waters from which they come are warm: the average temperature is 24-30C (75-86F), according to Fishbase.org.  While they will survive in an unheated bowl provided the room is decently warm, keeping them in an unheated aquarium seems questionable.

Some of the object in which Bettas are kept are too small for any fish.  They should have room to turn around easily and room to spread those magnificent fins of theirs.  Keeping these fish in an adequate sized and warm tank has advantages to the fishkeeper in addition to feeling good about the way you keep your fish.  Healthy fish display more, build bubble nests and check every nook and cranny of the aquarium for missed food.  They are much more interesting to watch, and a betta doing an aggressive display in a well lit aquarium is a truly stunning sight.

It doesn’t take that much effort to set up a small aquarium with a heater, and this fish will reward you well if you do.  Secondhand equipment can often be bought for less than new equipment and a 2 gallon aquarium is more than enough space for a Betta.

Least Killifish, Heterandria formosa: Ideal for Small Aquariums or Bowls

This is a very small fish native to North America which is related to the guppy.  The Males are extremely small at 3/4 inches, and they prefer normal tropical tank temperatures of 68-78F.  Their small size and tolerance of moderate temperatures makes them ideal for a small unfiltered aquarium, provided it is not subjected to cold temperatures.   The largest problem with these fish is likely to be finding them, since they are not common in aquarium stores.

Invertebrates: Better Than Fish for a Bowl

Freshwater invertebrates may work well in truly tiny tanks if you do not wish to keep fish.  Freshwater shrimp are harassed by many fish species and may do better on their own.  There are also many species of snail, and a shrimp-like creature known as Triops.  Different species have different temperature tolerances, but some of them tolerate cool water very well.  You could also try brine shrimp if you are willing to handle very salty water.

Note

All temperature information is taken from fishbase.org, and are the temperatures at which the fish have been found living in the wild.  Some species can tolerate wider ranges.

Southeast Asia
Barclaya longifolia: Burma, Thailand, Vietnam
Ceratophyllum demersum (hornwort): worldwide
Ceratopteris thalictroides (oriental water fern): tropics, worldwide
Cryptocoryne affinis: Malay peninsula
Cryptocoryne cordata: Malay peninsula
Cryptocoryne pontederiifolia: Sumatra, Borneo
Hygrophila corymbosa: India, Malaysia, Indonesia
Hygrophila difformis (water wisteria): India, western Indochina
Limnophila sessiflora: tropical Southeast Asia
Microsorium pteropus (java fern): tropical Southeast Asia
Nymphaea lotus(Egyptian waterlily): East Africa, Madagascar, Southeast Asia
Riccia fluitans (crystalwort): worldwide
Rotala rotundifolia (Tooth-cup): mainland Southeast Asia
Vallisneria spiralis (corkscrew Vallisneria): tropics and subtropics
Vesicularia dubyana (java moss): India, Malaya, Java
Ceratophyllum demersum (hornwort): worldwide

South and Central America
Alternanthera reineckii (copperleaf): tropical America
Cabomba aquatica (fanwort): Northern South America to southern North America
Cabomba caroliniana ( Carolina fanwort): South America to southern North America
Cabomba piauhyensis: Central and South America.
Ceratophyllum demersum (hornwort): worldwide
Ceratopteris thalictroides (oriental water fern): tropics, worldwide
Echinodorus amazonicus ( Amazon sword plant): Brazil.
Echinodorus bleheri: tropical South America
Echinodorus horemanni: southern Brazil.
Echinodorus osiris: southern Brazil
Egeria densa (Brazilian waterweed): Argentina, Paraguay and Brazil
Hemianthus micranthemoides: Cuba, southeastern USA
Heteranthera zosterifolia (Mud plantain): eastern South America
Hydrocotyle leucocephala (water pennywort): Brazil
Ludwigia repens (water primrose): tropical North America and Central America
Myriophyllum aquaticum (water milfoil, Parrot’s Feather): South America, naturalized in Southern North America
Riccia fluitans (crystalwort): worldwide
Sagittaria subulata: American east coast, parts of South America
Samolus parviflorus (water pimpernel): North and South America, West Indies
Vallisneria spiralis (corkscrew Vallisneria): tropics and subtropics

North America

Bacopa caroliniana (water hyssop): southern, central USA.
Cabomba aquatica (fanwort): Northern South America to southern North America
Cabomba caroliniana ( Carolina fanwort): South America to southern North America
Ceratophyllum demersum (hornwort): worldwide
Ceratopteris thalictroides (oriental water fern): tropics, worldwide
Didiplis diandra (water purslane): North America
Echinodorus cordifolius: central and southern North America, Mexico
Hemianthus micranthemoides: Cuba, southeastern USA
Ludwigia repens (water primrose): tropical North America and Central America
Myriophyllum aquaticum (water milfoil, Parrot’s Feather): South America, naturalized in southern North America (not native there)
Nymphoides aquatica (banana plant): Florida.
Riccia fluitans (crystalwort): worldwide
Sagittaria subulata: American east coast, parts of South America
Samolus parviflorus (water pimpernel): North and South America, West Indies
Shinnersia rivularis: Northern Mexico

References:

Scheurmann, Ines. Aquarium Plants Manual. Barron’s

Glass gravel is an example of a tank furnishing which is potentially sharp. While such gravel may be completely irrelevant to fishes that spend all their time in Mid-water or near the surface, glass gravel is not recommended for use with fish that burrow or dig in the gravel, such as corydoras catfishes, because it can cut their barbels. Open wounds are an invitation to infections which could potentially kill your fish. Some china aquarium ornaments may also be sharp. Check your ornaments before you put them into the tank, and if they break check the broken edges. Sandpaper can be used to smooth sharp edges.

There are several types of tank furnishings that are likely to alter the PH of the tank. In some cases this may be good, it may be exactly why you bought them in the first place, but it is necessary to know what effect they have and keep an eye on it. Driftwood and peat adds tannins to the water making it it softer and more acidic. This may add a slight yellow colour to the water, and is useful for keeping and breeding acid water fishes such as many tetras. However, it is a good idea to watch the PH. I live in an acid water area and I love to use driftwood in my tanks. I keep acid water fishes, but I find that the PH has a tendency to drop very low when using driftwood, to the point where I sometimes have to add an agent to make the water more alkaline.

Shells, crushed coral and soluble alkaline rocks such as limestone or calcite increase water hardness and pH. If you are trying to keep Rift Lake Cichlids or marine fishes, this may be exactly what you want, but again, the pH must be watched and prevented from becoming too extreme for the fish you are keeping.

Certain materials are toxic to fish and can leach into the water. Copper is toxic to fish so pennies and ornaments made out of copper are not safe for your tank. Lead is also toxic and can leach into water. For this reason, objects made out of lead are a bad idea, and objects with a lead based paint could also potentially harm your fish.  Decorations bought from an aquarium store should hopefully be free of major toxins, but ornaments designed for other purposes may or may not be.  If in doubt, don’t put it in your tank.