Good freshwater pet for kids.

January 6, 2011 5:37 AM

What would be a good low maintenance freshwater fish that would thrive in a 2 gallon kids aquarium with a bubbler but no heater?

Goldfish produce too much ammonia and most fish need a warm water environment.

posted by boby to pets & animals (17 answers total)

Two gallons is tiny. And just a bubbler (no filter?). Get some guppies. They'll survive pretty much anything.
posted by le morte de bea arthur at 6:00 AM on January 6, 2011 [1 favorite]

A betta. They're fine with room temperature water and naturally live in tiny spaces. You can probably skip the bubbler, but the tank should have a filter.
posted by Silly Ashles at 6:03 AM on January 6, 2011

White cloud mountain minnows are freshwater, commonly available and pretty hardy, but they'll be happier - and healthier - in shoals of at least 5, which wouldn't fit in your aquarium. That's a problem you're going to run into with most if not all cold water fish that are small enough individually for your aquarium; if there are exceptions, I can't think of any.

Is adding a heater absolutely out as an option? Small heaters are pretty cheap, and a betta would be a great choice of fish for that aquarium.
posted by Catseye at 6:06 AM on January 6, 2011 [1 favorite]

Disagree strenuously on the betta. Bettas have evolved to survive in tiny spaces, which is not the same thing as thriving in them. In the wild, bettas live in rice paddies, ponds, and other shallow but broad bodies of water. They're also tropical fish and in a temperate setting will be much more sluggish and prone to illness. I wouldn't keep a betta long-term in anything smaller than a heated, filtered 5 gallon tank.

Contrary to popular belief, it's easier to manage larger tanks than small because the water quality is much more stable; it takes longer for toxins to build up in the water and it's easier to maintain a stable nitrogen cycle so that beneficial bacteria convert ammonia to nitrite and nitrate. In a two gallon tank the toxin level will spike very quickly, and losing track of things for a few days could easily mean the illness or death of your fish.

Plus, as you're aware, most fish require heaters, and though there are heaters available for tiny tanks, they don't have temperature adjustment settings, so turning them on and off is the only way to regulate them. That means the temperature swings up and down as the water warms, you realize it's too hot and unplug the heater, the water cools down, you turn the heater back on ... fish like stability.

If you're relatively new to fishkeeping, I would say get a bigger tank and the appropriate heater/filter. Alternatively, if you're not dead set on actual fish, you could keep dwarf shrimp or an African dwarf frog, which I am pretty sure can go without heaters as long as your area/room isn't too cold (but if you're interested, do double-check).

If you feel you have the experience, perhaps ricefish or least killifish/dwarf livebearers? Do some research and see what other people are keeping in their nano tanks. If you go this route you'll probably have to plant your tank heavily.
posted by bettafish at 6:53 AM on January 6, 2011 [2 favorites]

Guppies.
posted by infinitywaltz at 6:56 AM on January 6, 2011

Sorry, I missed the bit where you're looking for a kids' tank -- scratch the last paragraph about the nano tanks.
posted by bettafish at 7:05 AM on January 6, 2011

Goldfish produce too much ammonia

Not if you have a filter and keep the tank clean. There's no other fish that is going to not produce ammonia. Certainly none that tolerate worse conditions than the average goldfish.

There are filters that run via airpump for small tanks. They are not ideal, but they do make a difference.
posted by oneirodynia at 7:27 AM on January 6, 2011

They're not as pretty as most fish, but you could put a bunch of cherry shrimp in a small aquarium. They're light on the bio-load and they'll help keep your tank clean by eating algae. They're super low maintanance, too. You could probably add some even if the tank has fish.

I'd also recommend live plants. They'll help remove ammonia/nitrites/nitrates and your tank's inhabitants like them better. Plus they look cool!
posted by Tu13es at 7:34 AM on January 6, 2011 [2 favorites]

I work in the fish department of a pet store and run into this question all the time. The answer is, unfortunately, nothing. A two gallon tank is really too small to keep any fish and hope to get a decent lifespan. We accept returns on our fish for 14 days and it is extremely common for people to return dead bettas and guppies and white clouds withiin 5 or 6 days. Obviously there are people who manage to keep fish for longer than that but in my almost three years of working with fish, its very rare. And almost never happens when kids are the primary caretaker. Get a bigger tank, or get a couple plants and a couple snails.
posted by d13t_p3ps1 at 7:41 AM on January 6, 2011 [2 favorites]

Not a fish, but still swims Triops are pretty cool.
From the site "playful shrimp that look like horseshoe crabs and date back to the Triassic Period in fossil records."
posted by ljesse at 7:58 AM on January 6, 2011 [1 favorite]

Not if you have a filter and keep the tank clean. There's no other fish that is going to not produce ammonia. Certainly none that tolerate worse conditions than the average goldfish.

Goldfish produce way more ammonia than tropical freshwater fish of an equivalent size, and they don't necessarily tolerate worse conditions. If you had a heater on the tank – or if it's one of those tanks that has a hood with a built-in filter, which in my experience don't need heaters because the filter motor runs hot enough to heat a two-gallon tank – I'd suggest a betta. I've had bettas live for two to three years in a half-gallon bowl with no filter and no air pump. Of course, I was very diligent with cleaning and water changes, but still. The other options are guppies and white cloud minnows, which are comparatively small and hardy, but they're still a gamble, as d13t_p3ps1 points out, and probably not as good an idea as a betta, especially if your kid plans on naming them.
posted by infinitywaltz at 11:30 AM on January 6, 2011

When I was a kid, I inherited a 2.5 gal tank (bubbler, no heater) and a kissing gourami of indeterminate age from a friend who was moving out of state. I managed, as a preteen, to keep it alive for a couple of years. It eventually died of Ich, which is apparently much harder to prevent/control/treat in a small tank w/ more frequent water temp changes.

That said, I honestly don't think I'd recommend such a small tank. They really are difficult to manage compared to the larger tanks.
posted by somanyamys at 12:20 PM on January 6, 2011

White clouds!

Both bettas and guppies, although good in small spaces, are tropical fish which require water temperatures in the upper 70s/low 80s. The same goes for neon tetras, and a lot of the other small fish you find at the pet store.

However, white clouds are a fish which come from high mountain streams. They do best in water temps between 65 and 70 - which is to say, room temperature.

You can get away with putting 5 in there, as long as you change the water regularly. At least once a week.
posted by ErikaB at 1:13 PM on January 6, 2011

Why do they sell small fishtanks if nothing can live very long in one?
Thanks for all the suggestions.
posted by boby at 1:16 PM on January 6, 2011

The other thing is, without a filter, if you have fish - or even if you don't - that water is gonna get murky very quickly and will require frequent, partial changes.
posted by smoke at 2:10 PM on January 6, 2011

Why do they sell small fishtanks if nothing can live very long in one?

Because they don't care whether or not the fish live long, healthy lives -- just that they can make money off of inexperienced fishkeepers who don't realize that it's healthier for the fish and easier for the owners to have a larger tank.

Or, even more cynically, because the sooner the fish die the sooner you have to come back and buy more.
posted by bettafish at 9:29 PM on January 6, 2011

Goldfish produce way more ammonia than tropical freshwater fish of an equivalent size, and they don't necessarily tolerate worse conditions.

The ammonia thing is a myth. Per weight, they do not produce more waste than other fish. Goldfish are often fed cheap food loaded with fillers, and in those cases produce more waste than they ought. In higher temps their metabolism increases, and so does the amount of waste they produce. However, the latter is true of all fish: increase metabolism, cells produce more waste products. They will also excrete more if water salinity is increased over 6%, probably because it stresses them.

I also did not say that goldfish tolerate worse conditions than other fish, I said that there is no other fish that tolerate worse conditions; as in: there are no other fish that will allow you to spend less time caring for them/changing their waiter/feeding them carefully/&c. than a goldfish. That's not the same.
posted by oneirodynia at 1:12 PM on January 7, 2011