3 gallon tank idea

[Perthegallon]

Dwarf seahorses are another great suggestion for this tank!! Seahorse savvy sells CB babies, but they eat live baby brine and need to be fed multiple times a day. So somewhat specialized care but very cute and a great suggestion

I can definitely do that i hatch live brine a lot

 

[Perthegallon]

Huh, a jelly tank. That would still work OK for a single tiny saltwater goby, since they hop around in all directions and don't need a lot of back-and-forth space, but ABSOLUTELY do not put any freshwater fish in there. Freshwater fish need space to move horizontally.

Yeah horrible works for jellyfish doesnt keep them suspended at all

 

[Perthegallon]

I'm more concerned about how flow patterns in that tank work. Like...it's obviously based off of something like a kreisel design. But is the water supposed to flow upwards and through the grates from somewhere? If there's a grate at the bottom, that will need to be not blocked (no substrate).

Dwarf seahorses might do well in the tank, and you could probably use it as a rearing tank for some fish larvae. But a lot of the species we discussed previously are going to be out due to the tank not being a standard rectangular prism.

Ctenophores might work, but they're going to need to be kept cold. I'm attaching a Jelly Care Manual if you go this route.

Ive kept jellyfish for over 3 years I cant do it anymore the jellyfish are tanks are horrible and dont work

 

[Sharkbait19]

For fw fish maybe a betta and a dwarf frog. That’s what I have and they’re pretty happy. Other options include certain livebearers, white cloud minnows, and zebra danios, though that’s a bit of a stretch. There’s also species catfish that can go in those tanks, though they’re not quite common.

If you can keep up with frequent water changes then maaaaybe you can do a dwarf pufferfish, if you want something interesting.

You can also just do fancy shrimp and snails. They’re always really fun to watch!!

However, no freshwater fish should really have that small a tank, and I would not recommend any of those options for any of the fishes’ lifespans. Those are just possibilities. The only 100% FW option that I can think of that would definitely work is African dwarf frogs. They’re easy, inexpensive, hardy, and VERY fun to watch!! Only downside is they prefer shallow tanks, but you can keep high decorations to encourage them to live near the surface. Otherwise, get an air stone and some plants for oxygen.

 

[ichthyogeek]

For fw fish maybe a betta and a dwarf frog. That’s what I have and they’re pretty happy. Other options include certain livebearers, white cloud minnows, and zebra danios, though that’s a bit of a stretch. There’s also species catfish that can go in those tanks, though they’re not quite common.

If you can keep up with frequent water changes then maaaaybe you can do a dwarf pufferfish, if you want something interesting.

You can also just do fancy shrimp and snails. They’re always really fun to watch!!

Yes to the fancy shrimp, but a hard no on the cyprinids (minnnows, danios). I've kept them in standard 10 gallon tanks, and they just don't have enough space in those.

Most of those options would work if the tank was 3 gallons in a rectangular fashion. But the 3 gallon tanks designed for jellyfish hardly have enough footprint for most of the fish specified.

 

[Sharkbait19]

Yes to the fancy shrimp, but a hard no on the cyprinids (minnnows, danios). I've kept them in standard 10 gallon tanks, and they just don't have enough space in those.

Most of those options would work if the tank was 3 gallons in a rectangular fashion. But the 3 gallon tanks designed for jellyfish hardly have enough footprint for most of the fish specified.

Yeah, I agree. I definitely wouldn’t keep any of the fish in there for life, at least with those dimensions. Shrimp are fun though! And dwarf frogs, though it’s the same idea for the dimensions.

 

[Perthegallon]

For fw fish maybe a betta and a dwarf frog. That’s what I have and they’re pretty happy. Other options include certain livebearers, white cloud minnows, and zebra danios, though that’s a bit of a stretch. There’s also species catfish that can go in those tanks, though they’re not quite common.

If you can keep up with frequent water changes then maaaaybe you can do a dwarf pufferfish, if you want something interesting.

You can also just do fancy shrimp and snails. They’re always really fun to watch!!

However, no freshwater fish should really have that small a tank, and I would not recommend any of those options for any of the fishes’ lifespans. Those are just possibilities. The only 100% FW option that I can think of that would definitely work is African dwarf frogs. They’re easy, inexpensive, hardy, and VERY fun to watch!! Only downside is they prefer shallow tanks, but you can keep high decorations to encourage them to live near the surface. Otherwise, get an air stone and some plants for oxygen.

I feel like it would be inhuman to put a betta in a 2.5 gallon as that wouldn't give it enough space

 

[Tired]

Do NOT put zebra danios in that tank! They need 20 gallons, minimum. Livebearers all need 10-20 depending on species, except least livebearers, which are ok in 5. White clouds should go in a minimum 15, probably. Bettas, bare minimum 5, larger is preferable. Dwarf frogs, also a minimum 5 is good, and they're not great to mix because the frog can eat the betta's tail and the betta can bite the frog's toes. Moth catfish are tiny, but active enough that they need at least 5. Puffers, also 5 is probably a good minimum.
Please do not recommend fish and then immediately say you wouldn't recommend them. If someone has a tank that they want to put fish in, and asks what fish to put in that tank, only recommend fish that should go in the tank.

Shrimp are great options, and wouldn't mind the tank being tall as long as you had tall decor.

One option: opae ula shrimp. Very small brackish-water shrimp, extremely low-maintenance. They don't need or want a filter or heater. They're so small that their waste is used up if you have algae or macroalgae growing in the tank, so they don't need or particularly want water changes. Check out petshrimp.com for info. People keep and breed these lil guys in big vases that are just lit by sunlight, with no electricity involved in any way, and they do great. Super teeny. They don't need much space, they'll climb up and down vertical decor, they swim around, and they breed into little planktonic larvae which survive, settle, and grow into adults. I love 'em.

 

[Perthegallon]

Do NOT put zebra danios in that tank! They need 20 gallons, minimum. Livebearers all need 10-20 depending on species, except least livebearers, which are ok in 5. White clouds should go in a minimum 15, probably. Bettas, bare minimum 5, larger is preferable. Dwarf frogs, also a minimum 5 is good, and they're not great to mix because the frog can eat the betta's tail and the betta can bite the frog's toes. Moth catfish are tiny, but active enough that they need at least 5. Puffers, also 5 is probably a good minimum.
Please do not recommend fish and then immediately say you wouldn't recommend them. If someone has a tank that they want to put fish in, and asks what fish to put in that tank, only recommend fish that should go in the tank.

Shrimp are great options, and wouldn't mind the tank being tall as long as you had tall decor.

One option: opae ula shrimp. Very small brackish-water shrimp, extremely low-maintenance. They don't need or want a filter or heater. They're so small that their waste is used up if you have algae or macroalgae growing in the tank, so they don't need or particularly want water changes. Check out petshrimp.com for info. People keep and breed these lil guys in big vases that are just lit by sunlight, with no electricity involved in any way, and they do great. Super teeny. They don't need much space, they'll climb up and down vertical decor, they swim around, and they breed into little planktonic larvae which survive, settle, and grow into adults. I love 'em.

what do you feed them and what salinity?

 

[Salemsoul]

Caridina & Neocaridinia are very popular FW Shrimp & can be housed in tanks smaller than 5 gallons. Also there are some BEAUTIFUL color options

 

[Tired]

Like I said, look at petshrimp.com. Opae ula largely eat algae and biofilm, so you don't feed them. Unless you have tons, in which case a tiny pinch of any fish food once a week is good. Salinity is about midway between fresh and saltwater, they aren't picky. Easiest aquatic pet in the world, excluding marimo mossballs. Set the tank up with saltwater and rocks, wait a month or so for algae to establish, add shrimp, keep tank lit and topped off with distilled or RODI water, and that's it. Give them a year or so and they start breeding. Easier than some houseplants!

 

[Squeaky McMurdo]

Are there actual saltwater mollies? I know freshwater mollies can be acclimated to salt, but I've never heard of an actual black saltwater species.

Yes, mine were all wild caught at 1.020 off the Florida Coast. They are not black though. They are green sailfin mollies. All 3 are females though so don’t have the huge impressive dorsal fin the males do. I plan to put a lyretail male with them when I find a nice one in the hopes that both traits get passed on.

 

[Sharkbait19]

Do NOT put zebra danios in that tank! They need 20 gallons, minimum. Livebearers all need 10-20 depending on species, except least livebearers, which are ok in 5. White clouds should go in a minimum 15, probably. Bettas, bare minimum 5, larger is preferable. Dwarf frogs, also a minimum 5 is good, and they're not great to mix because the frog can eat the betta's tail and the betta can bite the frog's toes. Moth catfish are tiny, but active enough that they need at least 5. Puffers, also 5 is probably a good minimum.
Please do not recommend fish and then immediately say you wouldn't recommend them. If someone has a tank that they want to put fish in, and asks what fish to put in that tank, only recommend fish that should go in the tank.

Shrimp are great options, and wouldn't mind the tank being tall as long as you had tall decor.

One option: opae ula shrimp. Very small brackish-water shrimp, extremely low-maintenance. They don't need or want a filter or heater. They're so small that their waste is used up if you have algae or macroalgae growing in the tank, so they don't need or particularly want water changes. Check out petshrimp.com for info. People keep and breed these lil guys in big vases that are just lit by sunlight, with no electricity involved in any way, and they do great. Super teeny. They don't need much space, they'll climb up and down vertical decor, they swim around, and they breed into little planktonic larvae which survive, settle, and grow into adults. I love 'em.

Yeah, that wasn’t my intention to sound misleading. I was sorta saying “these things can be done, but it doesn’t mean you should”. I wouldn’t ever recommend any of those fish in such a small tank, it’s just possible. Honestly, for FW, I’d say do some cherry shrimp and blueberry shrimp. I had a tiny tank with them, and they’re pretty fun. Also Thailand micro crabs should probably work. Most snails are ok too, just not the big waste machines.

 

[Alaeriel]

I've got 4 neocaridina and a hitchhiker snail in a planted gallon paludarium (with the canister filter, probably close to 3 gallons volume) but I wouldn't do any type of saltwater shrimp or any type of fish at all in something this small.

 

[Sharkbait19]

I feel like it would be inhuman to put a betta in a 2.5 gallon as that wouldn't give it enough space

I agree. I never would, all I know is it is done by a lot of people.

 

[Tired]

I would argue that it's not possible. Not long-term. Especially zebra danios, they get really stressed in tiny tanks. And we should really not be recommending things that are technically possible, anyway- only things that are a good idea. Otherwise someone who's not very good at listening to advice is going to hear "you can do this" and go "I will do this".

I have a pico reef that holds about 3 gallons of water, all told, with the water displacement from the rocks. I have corals, crabs, and a tiny fish, all doing well. He's a trimma goby, they just perch. I don't have a shrimp yet, I'm trying to find a species that won't bother my corals too much like cleaner shrimp often do.

 

[Sharkbait19]

I would argue that it's not possible. Not long-term. Especially zebra danios, they get really stressed in tiny tanks. And we should really not be recommending things that are technically possible, anyway- only things that are a good idea. Otherwise someone who's not very good at listening to advice is going to hear "you can do this" and go "I will do this".

I have a pico reef that holds about 3 gallons of water, all told, with the water displacement from the rocks. I have corals, crabs, and a tiny fish, all doing well. He's a trimma goby, they just perch. I don't have a shrimp yet, I'm trying to find a species that won't bother my corals too much like cleaner shrimp often do.

True. I’ve only done a small zebra danio tank for a month and it was upgraded very quickly when they fought. I probably sounded misleading here. Sorry, folks!!

 

[Tired]

You did list off some nice fish, which would (mostly) be good in a community tank. Obviously pea puffer aren't community fish, and bettas are iffy. White clouds do best in coldwater tanks, but IIRC danios also work in cold water? So a white cloud/zebra danio tank could work. It would have to be a lot bigger than this one, though. OP, if you decide you'd like a freshwater community tank at some point, 20 gallons is a nice size that gives you some good options and plenty of fish space.

 

[Sharkbait19]

Yeah, pea puffers are totally not community. Best I could say is fast moving peaceful fish as tankmates. The thing about pea puffers is their unpredictability, either being shy and docile or highly territorial. I had a tank with puffers and my big male puffer killed off the rest of them, then died from internal parasites.
My favorite puffer is the Amazon Puffer (colomesus asellus). However, they need tanks no less than 30 gallons for their schooling behavior and high activity. Also, keep them with docile fish. Though community fish, they can be picked on easily. A handful of tetras wound up picking on mine to the point of death, so be careful.
Just food for thought!!

 

[Perthegallon]

Yeah I’m starting to think there’s not much I can put in here other then shrimp