One fish, two fish
January 10, 2009 9:42 PM   Subscribe

I've finally equipped and decorated my new 55 gallon aquarium - and yet, I still don't know what kind of freshwater fish to populate it with.

This was an awesome impulsive buy, without any sort of fish in mind. Now I'm thinking that I'd like to make it a community tank, with fish occupying as many levels of the water as possible. Having something moving along the bottom, middle, and top sounds very interesting, but I'm clueless when it comes to which species can make this possible.

What would you recommend, keeping in mind I'm a relative beginner?
posted by Bakuun to Pets & Animals (22 answers total) 13 users marked this as a favorite
Well, it really depends on what kind of water you have. Some fish do better in hard water, so if you have really hard water, I think a community of South American livebearers like mollies, platies, or guppies would do really well. If you have soft water, you could do something similar with tetras and barbs. In either case, a school of corydoras catfish ("cory cats") would be a lot of fun to watch on the bottom.

You could also go for cichlids in a tank that large, African lake cichlids if your water is hard, or South American cichlids (like oscars or angelfish) if the water is softer. The thing with cichlids is that they have some really fascinating behavior, but they can also be really violent, so if you're a more sensitive soul, they're probably not for you.

Also keep in mind that to get the most out of a community tank, you're going to want to have at least six of each kind of fish; I'd probably recommend four or five schools of eight or nine fish each. Also, add one school at a time, waiting a few weeks before adding each group of fish, so that you can sort of keep an eye on how everything is going.
posted by infinitywaltz at 10:06 PM on January 10, 2009

I've always been partial to Angelfish.
posted by theantikitty at 10:21 PM on January 10, 2009 [1 favorite]

I've always enjoyed having a good little school of tiger barbs in my tanks. I've also had a very cool red tipped shark that I like quite alot. Really, the best thing to do is go to a good local shop and talk to them. Have them show you what would work and then choose what appeals to you. I like schooling fish but I've also thought that a tank with a bunch of crabs in it would be super cool.

Because you are new, stay away from any fish that costs more than five or ten bucks and stick with the lower end fish for now.

One additional word of caution on the cichlids. If the tank will be in your bedroom, you might want to think twice. My roomie from a few years ago had a cichlid that got really, really active at night, splashing and bashing into the tank walls. Kind of annoying.
posted by fenriq at 10:21 PM on January 10, 2009

Also, to keep things on the low-maintenance side of things, there are some really great tips in this article. Even the largest of his tank examples is less than half the size of your tank, but that's a good thing for you; larger tanks mean lower maintenance, and a lot of aquarium maintenance tasks like water-changing quickly lose their charm after you've been doing them for a while.
posted by infinitywaltz at 10:22 PM on January 10, 2009

Incidentally, I just looked at the picture, and that's a really pretty tank! Maybe don't get African cichlids, because they'll dig up the plants and screw up your decor.
posted by infinitywaltz at 10:24 PM on January 10, 2009

In the past I've been partial to livebearers and fancy goldfish (well, not in the same tank) but right now I'm having a lot of fun with blue rams. Lots of cichlid personality without aggression toward tankmates and they don't tear up tank decor.

Judging from the dates on your flickr photos, you added the water today. In case you don't know already, you'll want to cycle the tank before adding any fish. Cycling from scratch takes 4-8 weeks, so you've got plenty of time to think about what fish you're going to stock. While it seems like a long time to have an empty tank, it's worth waiting for the cycle to complete as it's a pretty turbulent process and waiting it out means you won't be stressing out (and probably killing) your new fish.

I like fishless cycling; it is humane as doesn't require sacrificial fish. Get a water test kit too, you'll need it both for the cycling process and future maintenance. This one will seem pricey but it tests for a wide range of stuff and the kit will last a very long time.
posted by jamaro at 10:33 PM on January 10, 2009 [4 favorites]

I'm very pleased with how my black neon tetra stay near the top and my serpae tetra in the middle. They haven't interacted with the placid bottomdwellers (clown loaches/bronze corydoras), but the serpae do chase each other regularly (which can be stressful for a new aquarist, but is harmless to the fish). Tetra won't hide except when sleeping, so I'd recommend sticking with them over fish with picky social and environment requirements that end up hiding anyway (gouramis, loaches, catfish). That's the breadth of my experience, at least.

I cycled with my serpae tetra and a full dose of refrigerated bio-spira. I was very impressed with the spira product and would use it over traditional cycling methods.
posted by cowbellemoo at 10:57 PM on January 10, 2009

One or two cooly loaches can really liven up a tank. They're eel-like and they move sinuously and vertically. Many are shy but others just like to boogie up and down the corners of the tank. If you're going the live bearer route infinitywaltz recommended then consider a pair of swordfish (they're a deep orange/red with black on their faces and the males have long "swords").

On the cichlids, people get very addicted to them. They can also get really enormous. Either way, they seem to take over.
posted by carmicha at 6:54 AM on January 11, 2009

It's hard to tell from your picture but those are fake plants right? You should try real plants. They help to keep the water clean and they look so much prettier.

Now I will answer your question.

Angelfish are great, they're active and easy to see. So are the sword tails, except ours won't stop making more fish (we sell the babies at our local store). Cichlids can be very destructive to your tank; your plants will be moved from the place you put them. Zebra Danios are great little fish that tend to stay at the top of the tank and we found some that are supposed to have jellyfish DNA that are hot pink. We have a clown loach that we see maybe once a week but when he makes his appearance it's worth it. Don't forget to get a pleco. They keep your tank clean, are nice to plants and other fish, and they get big quickly.
posted by shmurley at 8:23 AM on January 11, 2009

Corydoras catfish and "gold dojo" loaches
posted by Bigfoot Mandala at 8:27 AM on January 11, 2009

I agree with the suggestions of getting schools of fewer kinds of fish and cultivating a relationship with a good fish store - places like Petco often don't have anyone really knowledgeable working there. The suggestions about adding fish a few at a time and getting them only from a good place are spot on. The general rule is about one inch of fish per gallon of water. Fish are social and will be happier and more interesting to watch in schools.

Angelfish and barbs while beautiful can be very nippy - I've had bad experiences with both in tanks with more timid fish. Mollies, platies, swordtails, zebras and tetras will all get along. Platies and swordtails will have babies which is always fun, same with guppies. I'm very partial to plecostomos for controlling algae. They can get really big - I have two in my 29 gallon tank that have grown to 8 or so inches and will apparently keep growing up to about 24 inches. They do ok with a population of 3 different kinds of tetras and a Chinese algae eater though - they're big but don't mess with smaller fish and are the exception to the general rule of keep everyone around the same size to avoid the little ones getting eaten.

Goldfish and plecos both are prolific poopers - either will require more attention to tank maintenance than many others. I do a partial water change vaccuum/siphoning water every week or two. I use the water to water my plants.

Have fun - a 55 gallon tank is cool and you can do a lot of really creative stuff with it!
posted by leslies at 8:30 AM on January 11, 2009

If you get mollies, you will need to have some live plants for them to eat. They are really neat because they are livebearers - you will have lots of mollie babies swimming around your tanks. Plecos like live plants too.

Cichlids are pretty, but in my experience they like to move the gravel, rocks and plants around.

I am partial to cardinal tetras myself. They are like neon tetras but larger, with more red.
posted by Ostara at 8:41 AM on January 11, 2009

Best answer: I worked in the pet industry as a fish specialist for a while, so here's my take. YMMV, of course.

You can artificially accelerate the cycling process by adding commercially available cultures of nitrosomas etc. The most popular / widely available one is called "Cycle" from Hagen, but Marina brand stuff tends to be better quality. Another option is if you know someone who already has a tank, you can use a piece of their biological filter (if they're willing to lend it to you). When you begin cycling, you want everything _but_ the fish in place, so make sure the tank is planted with whatever plants you want. Typically, adding the bacteria from a culture reduces the wait to between 4-7 days for a complete cycle.

Once the cycling is done, there are tons of species you could go for. As always, check with the guy selling you the fish for compatible pH, hardness etc.. This varies not only between species, but between batches of each species the store receives (fish do best in water similar to the water they were raised in or have been living in for months).

Top of the tank:

Zebra Danios - These are the little "zebra fish" you see sold everywhere. They're hardy, available in a couple of interesting subtypes (glowing and longfin), and mix well with other fish. They may nip at fins if hungry or stressed. I would make them the first fish you put in your tank. They should have thin black lines down the length of their body. Pearl danios are basically the same, but yellower, and the lines are paler if present at all. Buy these guys in groups of 3+ to form a school. They are surface and mid-level feeders, but preferentially hang around at the top of the tank.

Gouramis - Get mature 3 inch gouramis for a new tank because they adjust better than the juveniles to new water chemistry. Gouramis are surface feeders and can be territorial. They should be kept in pairs or even-numbered groups so they can pair off, and there should be a good number of objects that each pair can claim as their own. Gouramis can be very shy, and counterintuitively, will be more bold, visible and active in a tank with lots of spaces (this is true of lots of smaller fish). They grow long fins and whiskers that nippers will love to go after, but a mature pair of gouramis can usually chase them off. A lone gourami may be picked on.

Scissortail Rasboras - scissortail rasboras are surface feeders, and are long lean little silver fish with black and white dots on their tail. They are nippy and fast, which makes them (and danios) ideal for more aggressive tanks filled with barbs. They're easy to care for and fairly hardy. They are a schooling fish and do best in groups of 3+ like the danios.

Mollies / Platies / Swordtails / Guppies - These are all livebreeding fish (they eat their eggs and raise the babies in the mother's mouth until they're large enough to be freeswimming, when she spits them out). They prefer water with a higher salt content than most other freshwater tropical fish, so I wouldn't keep them with the more delicate tetras / discus etc. Mollies are the biggest (topping out between 4-6 inches) and most aggressive, platies are smaller and less aggressive, swordtails are still smaller, and guppies are the smallest, usually no more than an inch and a half at full size. Each species is available in at least a dozen colour variations, from "Mickey Mouse" platies to "Red Wag" swordtails to black mollies. There are typically a variety of fin types as well, (Lyretail, regular, long fin, etc.) These are all very active fish and are best kept in trios - one male and two females so that the male's incessant attempts to mate won't wear out a pregnant female. The livebearers tend to be longer finned fish, and should be kept away from nippers like barbs (who are one of the few groups of fish that tolerate similar levels of hardness as the livebearers). Danios may be OK because they tend to be slightly less aggressive. Bear in mind the livebearers will breed in your tank, will have tons of babies, and something is going to need to eat those babies before your entire tank is a swarm of cute little blackish floating specks.


Tiger Barbs - Lots of folks like tiger barbs because they're hardy and easy to care for. Personally, they drive me nuts because they're aggressive schooling fish who will swarm and chase everyone else in the tank. If you do get them, they like harder water. They'll do less damage in a fully planted tank with lots of cover. Also, avoid the green tiger barbs you see for sale. They're a "colour morph" which means they've been highly inbred, and the quality of the ones you see at most pet stores is very low (If you look closely, you'll see many have crooked or deformed spines). Other species of barbs can be a handful (see: tinfoil barbs) or are weird crossbreeds (i.e. rosy barbs) or are engandered in their native habitat due to overfishing (i.e. cherry barbs) and I'd recommend staying away from them.

Tetras - Avoid neon and cardinal tetras (those little red and blue guys everyone wants). They are terrible for new tanks, and tend to be the prey of more hardy fish anyhow. What I would get instead are one of three species: Serpae Tetras, Black Tetras (sometimes called "Black-Skirted Tetras") or Head-and-Tail-Light Tetras. Of them, I like the black tetras the most personally. If you can keep those guys alive for a couple of weeks, I'd get silvertip tetras, glass tetras, and penguin tetras. Those three species look great, and grow to a decent size ~2in. where they're going to stop being prey-fish to other species. They're also hardier than neons, cardinals or glowlight tetras. Tetras are schooling fish that like really acidic water with lots of cover. Their colours won't come out properly if stressed, and they'll be much less active if they're not in a school. Just IME, but I find tetras tend to want bigger schools than other schooling fish, so instead of 3+, I'd get 7-10 tetras (also IME, different types of tetras will school with one another more easily than barbs will). Stressed tetras can nip, but it's rarer than with other types of fish.

Harlequin Rasboras - The little pink, yellow and black fish you can find in aquariums the world over. They're peaceful, they're easy to take care of, they like to school. I'd make them and danios the first fish you put in the tank if you decide to get them.

Rainbowfish - These are sometimes called "Bosmanis". They grow to about 4 in. typically, and are well behaved. They lose their colour when stressed, but they mainly just want soft, acidic water. They have lots of colour patterns, with red and blue variations the most common (I once saw a couple of really nice crimson-and-silver ones in a discus tank). These guys don't need a school, but they will group together if you get a bunch of them.


Corydoras - My personal favourite. Corydoras are not true catfish, and most species top out at 2-3 in. There are dozens of different types and subtypes with different colourations. They are a schooling fish, and one of my personal favourite sights in an aquarium is dropping in sinking pellets and watching fifty little corycats come squirming out of rocks and from underneath plants where they've hidden themselves to eat everything. They are bottom feeders and need to be fed using sinking pellets.

Clown Loaches - They get to be about 8 in. They aren't particularly predatory, but they may nibble on smaller fish. They are a scaleless botia and so are are very sensitive to changes in water chemistry (It's almost impossible to keep clown loaches alive in a tank that has had commercially available aquarium algaecide or antihelminthic drugs containing copper put into it). Other than that, they're great. They're very active, they're "pushy" enough that other fish will leave them be, even troublemakers like barbs, and they love to interact with the other fish in the aquarium.

Anyhow, I'll leave this incomplete and very eclectic list as it is just to give you some ideas. The only thing I have to add is to stay away from the following for your first tank:

Discus - Very fragile, and very expensive. Discus shouldn't go into a tank less than 6 mo. old anyhow. They're gorgeous, but they do demand a lot of care from someone with a lot of experience.

African / Midsize Souther American Cichlids - Very big, very aggressive, very demanding. Cichlids are again, something best kept by someone with a fair bit of experience who can tell when one is being picked on, or that the problem is that you've got two males that you thought were females, or that the "Green Severum" you bought is actually a Green Terror.

Angelfish - This will probably be the single most controversial thing I write in this post. I don't recommend angelfish for your first tank, or if you must, I recommend holding off getting them until your tank has been going for 6 mo. at least. They're not too difficult to take care of, but they act differently than many of the small tropical-community fish once they hit young adulthood. They get a bit more aggressive and predatory, they start trying to group off into pairs, and they keep on trying to lay eggs and chase everyone else out of the tank so they can spawn. They're a good fish for when you're saying to yourself: "OK, I have this tank under control finally, what can I add to change it up a bit?"

Anyhow, I hope that helps with some suggestions and ideas.
posted by Pseudoephedrine at 9:21 AM on January 11, 2009 [11 favorites]

Congratulations on your new tank! You've gotten a lot of good advice so far. I'm sitting here next to my 55 gallon tank, and I'll give the rundown of current inhabitants:

Gouramis: I have dwarf red gouramis. They swim at all levels in my tank, but mostly stick to the middle/top. Regular gouramis and dwarf gouramis behave very differently- dwarf gouramis are more peaceful than the larger ones.

Clown loaches: I've had my clown loaches since 2002 and they are doing great. The trick for clown loaches is giving them LOTS of places to hide- the more hidey holes they have a quick dash away, the more they come out to play. I have lots of live plants and four pieces of driftwood in the tank, and my loaches are out and about more often than not. Loaches have barbels that can be sensitive to rough gravel, or so I've been told, but I've never had any problems. They can be exquisitively sensitive to things like ich.

Plecostomus: A must-have, or you will be spending a lot more time on tank maintence. They do produce a copious amount of poop but I'd rather deal with that than be battling algae.

Boesemani rainbowfish: I have one lone rainbowfish. I rescued it years ago when my former employer decided to discontinue the fishtank maintenance contract on the tank in the reception area and just waited for the fish to die. ( Grrr.) He is the bossy eater of the tank. When I got him, I also had some dwarf neon rainbows, and the two did not get along well. It took me a while to figure out that mixing rainbows is not a good idea. A school of rainowfish are quite pretty though, and they are fairly easy to keep.

Otocinclus catfish: No one else has mentioned them, These little guys are personal favorites of mine- they are small and eat algae, like the pleco, but they can eat the algae off the plants without damaging the plants, whereas the pleco chomps holes in the leaves. None of the other fish take any interest in them, it's as if they don't even see them. Full size otocinclus are only about an inch and a half long. They help the pleco keep the algae in check.

A couple of things to keep in mind for a beginner- figure out what the water chemistry is for the water that comes out of your tap- you don't want to have to fiddle endlessly with pH adjusters- much better to stick to fish that are happy in the pH that comes out of your tap. You might consider picking up an extra heater to have on hand in case your heater craps out on you you have one ready to swap out instead of having to make an emergency run to the fish store. Also, you might want a small 5 or 10 gallon tank to have on hand for quarantine purposes, in case you get a sick fish or to keep new fish in for a while before adding to your main tank. I lost a whole tank to ich that way once, and then I got quarantine tank.

Have fun!
posted by ambrosia at 10:48 AM on January 11, 2009 [1 favorite]

Nice tank.

Don't ruin it with fish. They'll only poop in it.
posted by peabody at 10:59 AM on January 11, 2009 [1 favorite]

Response by poster: Hah! Peabody, that's genius. And exactly what my father suggested.

Pseudoephedrine, that's an incredibly helpful list, thankyouthankyouthankyou. I did add Nutrafin Cycle to the tank already, as recommended by the little store that sold me the aquarium itself. I'll be waiting a week before going with the first occupants, to be on the safe side.

Also, my father mentioned that I might need an air pump in there regardless of how good the filter is. (Which isn't an undergravel one - EHEIM ecco model.) Would it be beneficial to use an airstone, or is it an unnecessary expense?

Thanks again guys!
posted by Bakuun at 11:45 AM on January 11, 2009

An air pump isn't necessary, but it doesn't hurt. I like anything larger than a 33 gal. to have an air pump or a powerhead filter to keep aeration going unless it's heavily planted. The reason is that warm water holds less oxygen than cold water, and stressed fish need lots of oxygen. That's because when fish get stressed, the mucous coating on their gills thins (for many reasons), which interferes with how effectively they breathe. More oxygen helps reduce the stress of a move.

It also pushes water around. Since many tropical fish come from streams (well, originally, nowadays they mostly come from ponds in Thailand and Indonesia), they like the current. You'll find rainbows and thin-bodied tetras respond well to moving water, and will be more active as they interact with the current.

Rather than getting a lozenge-shaped airstone though, you may wish to try one of the "bubble curtain" stones, which are flatter and longer. Don't bother with one longer than 6 in. because commercial air pumps for aquarium use don't really generate a lot of pressure, so more than 6 in. isn't going to really create many more bubbles. I'd bury it under the gravel at the bottom on one side or another

Hope that explains things..
posted by Pseudoephedrine at 12:08 PM on January 11, 2009

Plecostomus, a funny looking, nigh-indestructible armored catfish.
posted by electroboy at 2:56 PM on January 11, 2009

Mollies / Platies / Swordtails / Guppies - These are all livebreeding fish (they eat their eggs and raise the babies in the mother's mouth until they're large enough to be freeswimming, when she spits them out).

I have to correct this: none the above-mentioned species of fish cultivate their eggs in this manner. It's far more interesting: the males have a specially adapted pelvic fin called a gonopodium which is essentially a little fish penis. The males can waggle this fin around and insert it into the vent of the female, fertilizing the eggs *internally*. The female carries the fertilized eggs in her ovaries as they develop (the female swells tremendously during this) and mature young exit the female as freely-swimming, egg-sack-less fish.

Fish! So cool!
posted by jamaro at 5:26 PM on January 11, 2009

Whoops, my bad. That is pretty neat.
posted by Pseudoephedrine at 9:16 PM on January 11, 2009

I agree with everything Pseudoephedrine said, including the angel fish. when I first got my 55 gal aquarium, numerous fish were subjected to an unready aquarium, and I feel really bad about it. I'm glad you being patient and making sure the tank is ready before you add fish. And Angel fish go completely insane when they grow up. I'd maybe try angel fish again now that I'm more experienced, but they'd be in a tank by themselves, not a community tank.
posted by jrishel at 5:38 AM on January 12, 2009

oh, and missed the livebearer description. Jamaro is right, but there are some pretty cool Cichlids do raise their young as described, called mouthbrooders, not livebearers.
posted by jrishel at 5:46 AM on January 12, 2009

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