Help me choose fish for my new tank!

September 3, 2010 12:03 AM

What freshwater fish options do I have for a 5 gallon tank?

I've finally decided to give my cat her own built in TV set by setting up a tank. I've got a 5 gallon tank that I've let run and added some Tetra Safe Start to, and after testing the water it's ready for fish. Or something else.

There's just one problem- I don't know what I want to put in there! I got the 5 gallon because it fits where I need it to fit, so I can't go up in size, nor do I want to. I've got a filter and a heater set up, and there's some gravel right now, but that's all. I would like to add a few live plants and some fish. I've been thinking of schooling fish like neon tetras, but I've read that they need a bigger tank for a decent sized school. I've also thought about a Betta, but I would like to have more than 1 fish and I've read that a 5 gallon will only support a Betta and a few shrimp. I've also considered a few (2?) African Dwarf Frogs and a few fish, but I don't know what fish would be compatible with them in such a small tank.

Basically, I just need to know some combinations of fish (or frogs, snails, shrimp) that are compatible with each other and can live comfortably in a 5 gallon tank.

posted by kro to pets & animals (15 answers total)

Tin-foil barbs are bright (tin-foil) and they're fast and they're pretty, they zip around pretty well. I'm I'm not mistaken, you can prevent fish from outgrowing a tank if you keep the same water in that tank ie if you *did* want the fish to grow, you'd take 20 percent of the water out of the tank and pour it off, put in new, the fish will grow. I've grown a few oscars and a few tin-foil barbs, a few other fish, by changing out the water in those tanks. It's been years -- decades -- perhaps someone has new information about this.

In any case, I"m about sure you can keep them to a size.

Look at the barbs and see if you like them. Happens I do but hey, different strokes. Talk to a guy in a good shop, he'll steer you right.

Have fun!
posted by dancestoblue at 12:40 AM on September 3, 2010

Killifish are happy in a small tank, if you can find a dealer that carries them. If not, you need to find a friendly community fish who isn't going to grow as it ages. I recommend fancy guppies or platys. You could safely put two pairs (or one pair of each) in your tank, along with a snail if you like. They are easy to take care of and breed readily in captivity, so be aware that your cat might become a grandmother.

If you put live rooted plants in there, you won't want a snail, as it will eat your plants. You would also need to think about lighting, and with lighting comes algae. For such a little tank, I would stick with floating plants. Regular room light, or a desk lamp if it's dim inside, will keep that alive. Chances are you'll get some free snails on your plants anyway, whether you want them or not. (I like free snails, because I have a tiny hungry puffer fish in my small tank, but I wouldn't recommend him as a starter fish.)

You will definitely need to do regular water changes to keep your fish healthy. The only way skipping changes could regulate fish growth is by making them too sick to grow. It's best to choose fish that are naturally little.
posted by Sallyfur at 1:14 AM on September 3, 2010

The advice about not changing the water is bad advice and harmful to the fish.
posted by proj at 2:36 AM on September 3, 2010

Definitely change the water regularly, you need to control ammonia build up even if you added the Tetra stuff.

If you're OK with just one fish, betta's are very easy to take care of. I have a small blue one in a 6 gallon tank with a small heater and he zips around a lot and is fun to watch. I just put in silk plants
since they're dead simple to take care of & you don't have to worry about algae and light levels and whatever.

(don't use plastic plants with bettas, you need live or silk plants so that their fins don't get ripped on the plastic edges)
posted by lyra4 at 3:00 AM on September 3, 2010

Yes, please don't listen to the "don't change your water" advice. That is the fastest way to kill fish, especially in a 5 gallon tank.
At my pet store, for 5 gallons, the only fish we really endorse putting in would be a betta.
Keep in mind with any fish you'll be doing weekly water changes, if you go the betta route you should be fine changing out about half the water each week. Clean the gravel out maybe once a month or so.
Another route you could go would be a small group of guppies, no more than 4. They'd probably be happier with 3. I would stick with all males, because you really don't reproduction happening in such a small tank.
You could get a pair of mollies or platys, and if you do this, you'll probably want to get both females. They aren't usually aggressive towards each other, but sometimes the males do fight and they don't really have anywhere to get away from each other.

As far as actually setting up the tank, put in everything except for the fish and let it run empty for a week. Make sure if you use tap water to treat it with water conditioner.
If you have any questions memail me, i love helping people set up tanks. It's the best part of my job.
posted by d13t_p3ps1 at 3:23 AM on September 3, 2010 [2 favorites]

I think the easiest way to figure this out is to just wander into your local pet store and see what you like. At least half of the fish are going to be fresh-water, and there will frequently be more than once species in a single tank.
posted by valkyryn at 5:43 AM on September 3, 2010 [1 favorite]

white clouds are a small fish that would work in a 5 gallon aquarium, the added bonus of being tolerant of a wide range of temperatures so you wouldn't need a heater, like a lot of the other suggestions.

5 white clouds, a dwarf frog, a mystery snail would make an interesting tank.

Also, the "don't change water" advice above is horrible. Yes, high ammonia levels will stunt a fish's growth. Also very likely to kill it.

If you want live plants in your 5 gallon aquarium, I'd let it run for least 6 months with fish before adding plants, ensuring your bio filter is running well. then get some red lava rock, and java ferns. tie the rhizome of the java fern to the lava rock with some thread. the java fern is very hardy and can make do with minimal light. it will root into the java rock before the thread rots away. the various Anubis strains can be planted the same way. this allows you to move the rocks around and clean the aquarium without worrying and disturbing their root system.

to control algae with your live plants, there are two main things you should do:
1) don't have the tank placed where it get's direct natural sunlight.
2) have your artificial light on a timer, that's on for less that 4 hours at a time. the theory behind this is that vascular plants photosynthesize as soon as they're exposed to light, but it takes about 4 hours of light for single cellular plants (algae) to really get up and running. So 3 hours in the morning around when you get up, 3 hours around noon, because plants really like sunlight at high noon, and 3 hours in the early evening.

If you've not had aquariums before, a larger tank might be a good idea. The more water in the tank, the more stable the system will be, so it is a lot more forgiving of your mistakes. Also, live plants complicate things as well, if you've never kept them before.
posted by jrishel at 6:12 AM on September 3, 2010

First, Google "fishless cycling" and read a few articles; learn about the chemical cycle of freshwater aquariums.
Then... start small; do not try to over populate the tank.

You might get an argument here or at your LFS (Local Fish Store) about the size of the tank. Except for a specialty tank (betta, killie, outgrow) a 5 gal is the smallest I would go. The idea is: larger the tank, changes happen more gradually. If something adverse happens, it is a lower percentage of the support system.
posted by Drasher at 6:40 AM on September 3, 2010

Oh, and be careful with the frogs.

There are two distinct types. One stays about the size of a quarter. The other grows into Gargantua, which will be too large for the 5 gal tank.

Know the difference.
posted by Drasher at 6:43 AM on September 3, 2010

I've had several solo bettas in big tanks... cats do enjoy watching them, they are gorgeous but they do require a little bit of added tank salt and a small low-power heater. Seconding the note on plastic plants: Get VERY soft silk fake plants, ones without sharp edges or pokey bits, as their tails will snag. Maybe rounded plastic ones would be okay. Bettas love plants, get quite a few at different heights. I don't know how well they would do with other species of fish, do some research on that one. (not only regarding temperament, but also re: the extra salt the bettas need)
Please change your water once a week. To do otherwise will kill your fish. Bettas especially need clean gravel (suction out poo with a turkey baster) because when they rest on the gravel, their long fins can easily get septicemia from the gunk along the tank bottom.
Also make sure you cover the tank with a secure screen, at least, if not a cover. Both to keep the kitty out and, well frankly, bettas are fierce jumpers, and many times leap out of the tank to their death. (T think the explanation is that they jump from rice paddy to rice paddy in the wild.)

Here's a great betta resource.
posted by mostlybecky at 8:40 AM on September 3, 2010 [1 favorite]

You can't confine a fish to a small space and make it stay small; it will die (and sooner rather than later). If you have naturally soft water, you would do well with some neons or other small tetras, but my suggestion would be either a small school of white cloud minnows (if you change a gallon of the water a week, you could probably keep eight of them or so) or guppies (of which you could probably keep up to six). Guppies are brightly colored, "jittery" in a way that's fun to watch for both cats and people, and most importantly extremely hardy, which is awesome if you've never kept fish before.
posted by infinitywaltz at 8:55 AM on September 3, 2010

My mom has a 6-gal Eclipse tank with bio-wheel filter and bubble wall which has sustained a group of 12 guppies for over a year; they periodically have babies but these never last long. They're bright and fast-moving!
posted by The otter lady at 9:50 AM on September 3, 2010

I had a little desktop Eclipse tank and it was AWESOME. I miss it terribly.

White clouds are awesome, and are my go-to fish for desktop tanks. They are not a tropical fish, like neon tetras and bettas. This means that they do not require warm water to be happy.

It's really really hard to heat a small tank effectively. Room temperature is usually 65-75 degrees, but tropical fish prefer water between 75-85 degrees. They can survive at cooler room temperature, but they won't be very happy - or very active.

White clouds, by comparison, have an ideal temperature between 65-75. Bingo!

I think they're pretty, too. Shop around until you can find the long-finned variety, sometimes called "meteor minnow."
posted by ErikaB at 12:00 PM on September 3, 2010

What is with bettas that they live in such small tanks? in regular pet stores they always put them in those tiny bowls. That can't be good for them, right?

For a five gallon tank, I'd choose the aforementioned guppies.
posted by DMelanogaster at 7:55 PM on September 3, 2010

I picked up a mystery snail and a few plants/decorations at the pet store on Friday. I've been checking the water since I started the smart start and everything looks good. I think I'm going to add two ADFs and 2 guppies when I go back to the store.

jrishel, I never would have thought of putting my aquarium lights on a timer, so thanks! I've had many fish tanks before, so no worries there.
posted by kro at 9:28 AM on September 5, 2010