Best and Worst Beginner Fish

I see a lot of people ask “what fish should I start with?” I also see a lot of people starting with fish that they were lead to thinking were easy.  Most people want a tank full of beautifully colored fish. I understand this, but often the most beautiful fish are also much more delicate. However, there are some very pretty and hardy fish with which you can start your hobby. They may not look like much in the store tanks, but once you get them home and into a good setup, they will show their true colors for you.

Through personal experience and discussion with other aquarists, I have gathered a list of fish that are good for the budding fishkeeper. These fish were chosen for their hardiness (ability to survive a cycle and live in less than ideal conditions), adaptability (can live in a wide range of parameters), small size (ideal for the first aquarium), and peacefulness. I have also compiled a list of fish that beginners should avoid for various reasons such as size, aggressiveness, and sensitivity.

Before I go into the fish, let me take a minute to explain what a good first aquarium size is. While bigger is always better, the beginner might not want to start with a massive tank of 55 gallons (209 L) or larger. This is a big tank (and a big expense), and big tanks mean big water changes which a new aquarist might not want. Conversely a 10 gallon (40 L) isn’t a great beginner tank because it is so small, and small tanks can have fast and dangerous water parameter swings. Also you can only fit one or two species of fish in a tank of that size. I’ve come to believe that tanks from between 20 gallons (75 L) and 40 gallons (151 L) make great beginner tanks because they are large enough to be mostly stable but not too large as to be a pain to perform water changes and they enable the first time fishkeeper to keep more than two species. 

The Bad Choices

Many fish that the pet stores tout as easy and great for beginners are far from that for many reasons. Some grow too large, some are hard to keep alive, and some are aggressive. Since there is a multitude of fish that would make poor first choices, I’m going to group them into categories and give you examples of fish that fall into these categories.

The first category of poor beginner fish are chosen because they get so large. They are sold as cute, inch-long babies, but they will soon be busting the walls of a normal beginner aquarium. These fish include goldfish (Carassius auratus auratus), common pleco (Hypostomus plecostomus), oscar (Astronotus ocellatus), and kissing gourami (Helostoma temminkii). Many people are surprised to see goldfish on this list because all you see in the stores are cute little goldfish. Trust me: these little golden wonders will soon be around a foot long and all the while they grow, pooping like a fiend. They are a hardy fish, but they just get too large for most beginners to handle.

You also don’t want to start off with a fish that is too sensitive. Oto catfish (Otocinclus macrospilus), angel fish (Pterophyllum spp), cardinal tetra (Paracheirodon axelrodi), and many more fall into this category. They should never be introduced to a cycling tank (tank where colonies of beneficial bacteria are not established and harmful levels of ammonia and nitrite are present) because they can’t handle the stress of a cycle. Oto catfish specifically need a setup that has had time to grow algae because they primarily eat algae. They come to stores starving because they are captured from the wild where they only eat algae. By the time they get to the store they haven’t seen any in weeks; they will starve to death in a brand new setup because it lacks algae.

Another mistake that beginners often make is buying fish that are too aggressive to keep with much else; they end up with a moderately large tank and nothing in it but a single school of fish. Or they buy a “freshwater shark” because the name sounds cool, and then end up with a tank full of fish cowering in the corner trying to stay away from the shark’s bullying nature. If you just want to keep a school of these fish or a freshwater shark, then go right ahead, but you won’t be able to add anything else to the tank. Fish that fall into this category are tiger barbs (Puntius anchisporus), black skirt tetra/black widow tetra (Gymnocorymbus ternetzi), and the freshwater sharks like rainbow shark (Epalzeorhynchos frenatus), bala shark (Balantiocheilos melanopterus), and red-tailed shark (Epalzeorhynchos bicolor).

Guppies (Poecilia reticulata) are a great beginner fish, right? You’d be surprised to learn that they are not. They were many years ago, but commercial scale breeding and continuous inbreeding has made what was once an extremely hardy fish into a weak, disease-ridden fish terrible for beginners. If you can find guppies from a hobby breeder, then you have the chance to get some good fish, but pet store guppies are so weak, they can hardly be considered a good fish anymore. Sadly, neon tetra (Paracheirodon innesi) and dwarf gourami (Trichogaster lalius) have also gone down this same route. Commercial-scale breeding programs are now producing weak, inbreed, and disease ridden fish. In fact, both fish now have a disease named after them because these fish so commonly carry them: dwarf gourami iridovirus and neon tetra disease. These diseases have no cure and can spread to other species.

I know you want to start off with strange and unusual fish to wow your friends, but these fish are usually delicate, difficult to keep alive, and have specific needs. This brings me to my final category of fish that are bad for beginners: the oddballs. These are fish like the black ghost knifefish (Apteronotus albifrons), German blue ram (Mikrogeophagus ramirezi), and African butterfly fish (Pantodon buchholzi). A good rule of thumb is if it looks strange, it’s going to be hard to keep alive. 

The Good Choices 

Don’t despair. While those are fish you shouldn’t start with, you have plenty of attractive and interesting options that can be your first fish. Instead of grouping them like the bad beginner fish, I have listed them out with pictures and general care information. All of these fish are not picky eaters and will readily accept any flake or pellet food.

Blue Tetra (Catxx @ the Aquarium Wiki)

Blue Tetra, Cochu (Boehlkea fredcochui)

Tank size: 20 gallons, 24 inches long (75 L, 61 cm)

Temp: 72 - 79F (22 - 26C)

pH: 6.0 - 8.0

Water hardness: up to 15 dGH

Notes: Like most tetra species this is a schooling species and needs to be maintained in groups of 6 or more. When buying schooling fish like this it is best to buy about 9 so in case you have a death, these fish won’t start bullying other fish. Don’t keep them with fish with long fins like betta fish. This fish will be most colorful in an aquarium with lots of cover such as decorations and plants (live or fake).

Group of Flame Tetra (Catxx @ the Aquarium wiki)

Flame tetra, Fire tetra, Von Rio tetra (Hyphessobrycon flammeus)

Tank size: 20 gallons, 24 inches long (75 L, 61 cm)

Temp: 72 - 82F (22 - 28C)

pH: up to 7.8

Hardness: up to 25 dGH

Notes: This is another gorgeous and hardy tetra species. They should be kept in a minimum of 6, but keeping them in larger numbers will make them more attractive and reduce the nipping tendencies common with tetra. Don’t keep them with slow-moving fish. It will show its best colors in an aquarium with lots of decorations such as fake or live plants.

X-ray tetra (Debivort @ Wikipedia)

 

Pristella tetra, X-ray tetra, X-ray fish, Goldfinch tetra (Pristella maxillaris)

Tank size: 10 gal, 20 inches long (40 L, 50 cm)

Temp: 74 - 82F (24 - 28C)

pH: up to 8.0

Hardness: up to 30 dGH

Notes: In my opinion, this is one of the best beginner fish because it is so easy to keep. It will survive in all but the most hard of municipal water supplies. Like all tetra, it should be kept in groups of 6 or more at a minimum.

Bronze cory cats (public domain)

Bronze Cory Cat, Albino cory (Corydoras aeneus)

Tank size: 20 gal, 24 inches long (75 L, 61 cm)

Temp: 70 - 80F (21 - 27C)

pH: 6.0 - 8.0

Hardness: up to 20 dGH

Notes: Also found in an albino form, the bottom-swimming bronze cory is a great addition to a new fishkeeper’s aquarium. They will do best with a sand bottom but can manage with smooth gravel. It will be most active when kept in groups larger than 5. Three is the minimum that should be kept together as these fish are very social.

Two harlequin rasbora (Stee @ flickr)

Harlequin Rasbora, Red rasbora (Trigonostigma heteromorpha)

Tank size: 20 gal, 24 inches long (75 L, 61 cm)

Temp: 70 - 82F (21 - 28C)

pH: below 7.5

Hardness: up to 15 dGH

Notes: A common fish in pet stores, it is a great choice for a beginner. This is another social fish that needs to be maintained in groups of 6 or more, but it will fare best with groups of 10 or more.

Two Bandit cories (Stuart Halliday)

Bandit cory, Masked cory (Corydoras metae)

Tank size: 10 gallons, 20 inches long (40 L, 50 cm)

Temp: 70 - 77F (22 - 25C)

pH: up to 7.5

Hardness: up to 15 dGH

Notes: As they are more shy than bronze cories, they should be kept in groups of 6 or more. They will be much more active in larger groups. When kept singly or with 1 or 2 other bandit cories, they will not be seen much and may be too shy to feed. They like a sand bottom best as they enjoy rooting around in the sand for morsels of food.

Regular zebra fish (public domain)

Glofish, genetically modified zebra danio (www.glofish.com)

Zebra danio/glofish (Danio rerio)

Tank size: 20 gallons, 24 inches long (75 L, 61 cm)

Temp:  65 - 77F (18 - 25C)

pH: 6.0 - 8.0

Hardness: up to 20 dGH

Notes: Also sold as the brilliantly colored glofish, these peaceful little schoolers make a much better candidate for a smaller unheated aquarium than goldfish do. The zebra danio that are sold as glofish aren’t dyed. They are actually genetically engineered to be that way by having jellyfish and coral genes implanted in their own. They will pass this down to their children, too. Like all schooling fish, these active little swimmers need at least 6 of their own kind to feel safe (you can mix glofish and the regular zebra danio). As a precautionary, I feel like I need to mention that due to massive inbreeding, this fish are becoming less and less hardy; one day they might not be good beginner fish.

Glowlight tetra (gonzalovalenzuela @ flickr)

Glowlight tetra (Hemigrammus erythrozonus)

Tank size: 20 gal, 24 inches long (75 L, 61 cm)

Temp: 74 - 82F (24 - 28C)

pH: up to 7.5

Hardness: up to 15 dGH

Notes: Like all the other tetra, this little beauty is a schooling fish and should be kept in groups of at least 6, but if you have the room and biological capacity add as many as you can. They are most colorful in large groups. An albino form is also seen and is just as hardy as the normal form. The albinos will school with the regular glowlights.

School of bloodfin tetra (public domain)

Bloodfin tetra (Aphyocharax anisitsi)

Tank size: 20 gal, 24 inches long (75 L, 61 cm)

Temp: 64 - 82F (18 - 28C)

pH: 6.0 to 8.0

Hardness: up to 30 dGH

Notes: This fish gets my vote as the best beginner species. It can survive a wide range of water parameters and is commonly found at petstores. Kept in groups of 6 or more, its brilliant red fins will sparkle in the water.

Male cherry barb (Sannse @ wikipedia)

Cherry Barb (Puntius titteya)

Tank size: 20 gallons, 24 inches long (75 L, 61 cm)

Temp: 74 - 81F (23 - 27C)

pH: 6.0 to 8.0

Hardness: up to 20 dGH

Notes: Barbs, like tetra, need groups of 6 or more to feel safe. They will be more colorful and be out in the open more if they have large groups. Unlike the tetra, the males are more colorful than females. The males have a much more red color while the females take on a yellow-brown hue.

Male swordtail on left; female on right (MacAnthony @ flickr)

Swordtail (Xiphophorus hellerii)

Tank size: 29 gallons, 30 inches long (109 L, 76 cm)

Temp: 68 - 82F (20 - 28C)

pH: 7 to 8

Hardness: 9 - 30 dGH

Notes: As this fish is a livebearer it is the best choice for a new aquarist with hard water. The catch is, if you put males and females in a tank together, you will get more swordtails. If you don’t want baby fish, get only males. If you want baby fish, make sure there are 3 females to every male. Males are also the more attractive of the sexes, so an all-male tank would be ideal for a beginner. Pretty and you don’t have to worry about babies.

These next two fish are good beginner choices, but they come with a catch which I will highlight in italics.

Male betta (copperarabian @ deviantart)

Betta fish/Siamese Fighting Fish (Betta splendens)

Tank size: 5 gallons (18 L)

Temp: 76F - 84F

pH: 6.0 - 8.0

Hardness: up to 20dGH

Notes: Betta fish are a great first fish if they are the only fish in the tank. They are very hardy, easy to care for, and will generally take any beginner mistakes in a stride. Their small tank requirement also makes them great as a dorm pet. Due to their aggressive nature, keeping betta with other fish makes the difficulty go up and can be a bit much for a new fishkeeper. Keep him in his own 5 gal tank and you will have an easy setup with a very interactive fish.

Male honey gourami (Kooshking @ flickr)

Honey gourami (Trichogaster chuna)

Tank size: 20 gal, 24 inches long (75 L, 61 cm)

Temp: 72 - 82F (22 - 27C)

pH: 6 - 7.5

Hardness: up to 20 dGH

Notes: This little jewel is the smallest and most peaceful of the gourami. It will make a great centerpiece fish in a small tank provided it is the only gourami in the tank. This also includes bettas as they are gourami, too. Male gourami are territorial and will fight when placed in the same tank. The males are the most colorful, so just one would be the perfect addition to a beginner’s tank.

Don’t feel limited by what the pet stores tell you are good beginner fish (because they are often wrong). The beginner has many attractive options for their first fish tank. As I discuss in my How to Stock a Fish Tank article, combining a species of cory cats and a school of tetra in a 20 gal tank could make a very nice display for the first-time aquarist. While not all of these fish may be available at your local pet store, I’m sure you will be able to find some of them to help you get started in your fishkeeping hobby.

Works Referenced

Monks, Neale. 2008. “Fish Viral Disease.” www.fishchannel.com. Retrieved 28 May 2012.

Monks, Neale. 2011. “Neon Tetra Disease.” www.fishchannel.com. Retrieved 28 May 2012.

Ramsey, Graham. 3 March 2010. “Top Ten – worst beginner fish.” fcas.wordpress.com. Retrieved 27 May 2012. 

Be careful of that label!

Why research is always needed before a fish purchase

When the average first time aquarium keeper walks into a pet store, they completely trust the employees there. Sometimes that trust is well placed, and the budding aquarist walks out with a 29 gallon (109 L) tank, some lovely X-ray tetra (Pristella maxillaris), and a water parameter testing kit. Other times, the new (and soon to be disappointed) aquarist walks out with a 20 gallon (75 L) tank, a pleco, an oscar, and—worst of all—a black ghost knife fish. (If you didn’t cringe at that, don’t worry, you soon will.)

In this particular article I’m going to be using Petsmart and Petco as examples simply because I know these stores best. They are the large chain pet retailers that I have closest to me. This is in no way intended as a stab at these stores because while there is a lot of bad information, they also have some proper information on the labels of the fish they sell. I am highlighting particular instances where the label is grossly wrong as an example of why research is needed or you may end up with more than you bargained for.

Clown Loach (Chromobotia macracanthus)

As adults, the vibrant colors of clown loach fade (Public Domain)

I’m going to start with my favorite fish of ones I’m highlighting today: the clown loach. Entertaining and active, these guys would make a great addition to your home aquarium, right? Wrong. Like so many of these tankbuster species, the little clown loaches you see at the store are babies. Probably less than a few months old. Now let’s compare Petsmart’s and Petco’s care advice for these species versus the advice from the loach experts over at Loaches Online.

	Loaches Online	Petsmart	Petco
Min tank size	180 gal (680 L)	40 gal (150 L)	50 gal (190 L)
Adult Size	12 inches (30 cm)	12 inches (30 cm)	12 inches (30 cm)
Hardness	1-12 dGH	NOT SHOWN	NOT SHOWN
pH	6.5 - 7.0	NOT SHOWN	6.0 - 7.5

As you can see there are some major discrepancies. Loaches Online’s veteran clown loach keepers recommend the smallest tank juveniles (which are what is sold in stores) be housed in is a 55 gallon (208 L) tank with biweekly water changes because these fish are active swimmers and any less will cause stress and stunting, but this should only be temporary housing. And the fact that some of the parameters such as pH and hardness aren’t even given in the Petsmart and Petco labels is also unsettling as the wrong pH and hardness can stress a fish to death. Sadly, I found this to be a constant with the Petco and Petsmart labels. Another surprising constant I found through the Petsmart and Petco care sheets was proper temperature for these fish, but this is only part of what is needed to keep a fish healthy. You can’t complete a puzzle without all the pieces.  

Fortunately, if you like the look of this fish there are some loaches that stay small enough to fit in the average home aquarium. The yoyo loach (Botia almorhae), angelicus loach (Botia kubotai), zebra loach (Botia striata), and Burmese loach (Botia histrionica) all have a similar shape and personality to the clown loach. If you search by the scientific name, you can find pictures of these cute, colorful fish. The only difference between these guys and the massive clown loach is that these guys can safely live their complete lives in a 50 gallon (190 L) tank which is a much more common and manageable size home aquarium.

Pleco, Plecothemus (Hypostomus plecostomus)

Mature pleco (Derek Ramsey @ Wikipedia)

The main reason people buy this fish is for its algae-eating abilities (I will go into why this is bad in a later article). Yes it does eat algae when small, but as it grows it begins to also eat lots of protein. This can easily mean small fish; it has also been known to attach to larger slow-moving fish like goldfish (Carassius auratus auratus).  Let’s compare what the expert fish keepers over at Tropical Fish Keeping.com have to say about plecos versus the Petsmart and Petco labels.

	Tropical Fish Keeping	Petsmart	Petco
Min tank size	55 gal (208 L)	55 gal (208 L)	10 gal (38 L)
Adult size	20 inches ( 50 cm)	24 inches (61 cm)	24 inches (61 cm)
Hardness	Less than 28 dGH	NOT SHOWN	NOT SHOWN
pH	6.0 – 8.0	NOT SHOWN	NOT SHOWN

While Petsmart did get the sizing right, I still see the associates selling these fish to anyone who asks for an “algae eater.” On the other hand, Petco falls very short here. Pleco need large tanks not only because of their size but also because they produce a lot of ammonia relative to body mass. They are comparable to goldfish in the amount of fecal matter and ammonia they produce. Again, neither of the chain stores mentions hardness or pH, two essential elements for keeping fish healthy.

Fortunately if you like the look of plecothemus, it has some relatives that can easily fit in your aquariums. The bristlenose pleco (Ancistrus sp) is similar in appearance and behaviour but only grows around 4 inches (10 cm) long. A single individual can be housed in a 10 gallon (38 L) tank or a pair in a 20 gallon (75 L). Groups need a 50 gallon (190 L) or larger tank as males can be territorial.

Black Ghost Knifefish (Apteronotus albifrons)

Juvenile black ghost knife fish
(Derek Ramsey @ Wikipedia)

While this is an interesting and unusual fish, this is a fish best left to be admired in public aquaria. Due to its large size, timid nature, and unique biology, this is not a good home aquarium fish, but it is still sold as such. Let’s compare Petsmart’s suggested care to a knowledgeable fishkeeping site’s care.

	Tropical Fish Keeping	Petsmart
Min tank size	180 gal (680 L)	75 gal (284 L)
Adult size	20 inches (51 cm)	20 inches (51 cm)
Hardness	5- 15 dGH	NOT SHOWN
pH	6 – 8	NOT SHOWN

Due to the manner in which these fish use electricity, their spines are inflexible. They must have an aquarium that is at least three times its length and twice as wide as the fish is long.  A regular 20 inch (51 cm) fish could hardly fit in a 75 gallon (284 L) aquarium let alone a fish with an inflexible spine. As with so many other species, Petsmart is falling very short on its care. At least Petco doesn’t carry this species.

For those looking for an alternative fish that still maintains the strange look of a knife fish, the African knifefish (Xenomystus nigri) is a good alternative that can be housed in a 55 gallon (208  L) tank. As all knifefish are rather delicate, this fish is not for the beginner aquarist and should be housed in a specialized setup. It is not for your typical community tank. Extensive research is suggested before buying this fish.

Pangasius catfish (Pangasius sanitwongsei)

Adult captured in Thailand (Matt Leete @ Fishbase.org)

Sometimes sold as an iridescent shark or paroon shark, they may look cute as babies at the store, but this is a species that is wholly unsuited for even public aquaria. A close relative of the massive Mekong giant catfish (Pangasianodon gigas), one of the largest freshwater fish in the world, any store that sells this fish and claims it can live comfortably in a home fish tank should be ashamed. This is a massive migratory and skittish species known for slamming into the tank walls when frightened. With specimens tipping the scales at 660 lbs (300 kg), a single fish could easily crack or break a tank wall.

	Seriously Fish	Petsmart
Min tank size	500 gal (1892 L)	75 gallons (283 L)
Adult size	48 inches (1.2 m)	25 inches (61 cm)
Hardness	2 – 30 dGH	NOT SHOWN
pH	6.5 – 7.5	NOT SHOWN

As you can see in this case, Petsmart falls very short of the care requirements of this species. Practical Fishkeeping is part of a movement called The Big Fish Campaign to spread awareness about this species and the other tankbusters like the tiger shovelnose catfish (Pseudoplatystoma spp), red tailed catfish (Phractocephalus hemioliopterus), and giant gourami (Osphronemus goramy). If you buy this fish and think you will just get a larger tank as it grows, think again. This species is known to live for 20 or more years and will need a tank as large as a medium moving van. And most public aquaria won’t take them when they outgrow your tank. This species is beyond their capacity to house long-term.

As you have seen, these two major pet retailers fall very short on their care sheets for these species. Many of these care sheets also cite the “gallon per inch of fish” rule which aquarists have known to be a poor stocking tool for a long time. Think about it this way, 10 inches of neon tetra aren’t the same as 10 inches of oscar. The 10 inches of neon tetra could easily be kept in a 10 gallon tank, but a 10 inch oscar would hardly be able to turn around. This rule doesn’t hold water when looking at fish larger than an inch or two because it doesn’t take into account the fish’s depth as fish grow in three dimensions, not just one. To be safe, I wouldn’t stock any tank based on this “rule.”

The only rule you can use to stock a fish tank is research, research, research. I hope these comparisons have opened your eyes to the need for it. I know there are many people who instinctively trust retailers, but as you have seen they cannot always be trusted to give you the correct information on your fish and in many cases are just trying to make a sale. In fact, telling you a fish needs a smaller tank that it should be housed in will cause the fish stress; stress leads to disease; and diseases are cured by medication bought from the store. See a pattern here? Always research before you buy!

Works referenced

Craig, Nicolette. 24 March 2011. “Who’s to blame for the big fish problem?”  www.practicalfishkeeping.co.uk. Retrieved 11 May 2012.  

Gay, Jeremy. 27 January 2012. “Will you support the Big Fish Campaign?” www.practicalfishkeeping.co.uk. Retrieved 11 May 2012. 

Hill, Nathan. 8 March 2012. “Where do all the big fish keep going?” www.practicalfishkeeping.co.uk. Retrieved 12 May 2012.

Monks, Neale. 2009. "Knifefish in the Aquarium." Tropical Fish Hobbyist (June): 86-90.

Fish Profiles referenced on 14 May 2012:

Clown Loach

• Petsmart
• Petco
• Loaches Online

Plecostomus

• Petsmart
• Petco
• Tropical Fish Keeping

Black Ghost Knifefish

• Petsmart
• Tropical Fish Keeping

Pangasius Catfish

• Petsmart
• Seriously Fish