Forgive me, FF, For I have Sinned... Paradise Fish Tank Size Confirmation

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Jamie D.

New Member
Feb 21, 2023
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Billings, MT
I've been away awhile - had surgery, had complications, lost King Louie (R.I.P), my beautiful pearl gourami to...something while I was barely caring for myself. Needless to say, my 38 gallon was looking a bit quiet with just the two plecos (clown and leopard frog) skulking around the bottom.

Anyways...went to the fish shop yesterday looking for some nice schooling fish and perhaps a honey gourami if they had a "real" one. Priscilla tetras caught my eye, and I bought eight of them, and then allowed myself to be talked into a "blue paradise gourami" they had in back instead of the honey I was looking at (*eyeroll*).

Yes, I know. A very tiny bit of research when I got home and then watching Eddie (Mr. Paradise Fish) do some initial chasing of the tetras drove home the stupidity of my impulse purchase. I am happy to say he's still a baby, so the tetras are currently the same size he is, and they're faster for the moment, so everyone seems to be tentatively getting along this morning. However, Eddie needs his own place, because I'm not willing to put the tetras at risk long term (I plan on getting 4 more if these do okay for the week), and I still want Sterbai cories for that tank, which from what I've read, he'd be a potential risk for them too when he grows up.

So...I have a stand that will fit a 20 gal. standard tank (or a 25 tall), and I've been planning on setting one up anyways (not for this, but hey, plans change). I know longs are generally better, but for Eddie's bachelor pad (and maybe a bristlenose - they seem to be listed as good tank mates consistently), will that be a decent amount of room? It will be heavily planted, of course, with sand substrate, rocks and driftwood. I have two tanks that really need to be thinned out, plant-wise, so that's easy enough.

I've read anywhere from 10 gal to 30 gal minimum for paradise fish on different sites, but 20 seems to be the most common. Given I've already sort of hosed this up though, I figured I'd confirm here before I go shopping, especially since all the different sites seem to list these guys at anywhere from 1.5 -4 inches when full grown, so I'm not even really sure what to expect there.

Thanks for helping me figure out how to fix my little impulsive mistake!
Yes, you certainly have an issue but fortunately you seem to be aware of it. It is however more significant than you may realize.

Fish do not need actual physical contact to be harmed by another fish. Fish communicate by sight, but also by chemicals called phermones (read by others in that species) and allomones (read by fish of other species). The stress this can cause to the neon tetras here is serious, and as harmful as physical interactions. There is only one solution, seperate out the paradise fish ASAP. The stress it is causing the other fish--and it does not stop with the tetras--will not go away until he/she does, and the tetras will slowly be weakened by such stress and this makes them more susceptible to health problems and guarantees a less than happy existence, albeit a shorter one as another result.

Fish bullies are created by us, the aquarist, when we force them into an environment that is not what they need and expect. They react the only way they can. In the natural habitat this usually plays out very differently because of the space and the lack of the other species which in the aquarium only serve to enflame the "bully." Another option of course is to return the paradise fish. There are more compatible tankmates, and a 30-inch tank for just one fish, well that is up to you.

As for tank size, these excerpts from my online profile of the species may help.

Compatibility/Temperament: Not a good community fish for the average aquarium. Smaller fish will be eaten, fins will be nipped, and any similar-looking fish will be attacked. Very aggressive with its own, males in breeding form will often kill rivals; females are less aggressive. Best kept as a pair on its own.​
Size: Normally around 3.5 inches, some males may attain 4 inches.​
Minimum Tank Suggestion: 30 inches in length (approximately 25 gallons).​

I hope your health is improving, I know first hand what this can do for one. Best wishes going forward.
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Thanks Byron. I do realize it's not just physical contact that's stressful (and one of my new Priscillas is obviously more stressed than the rest of the school), but unfortunately the LFS is closed Mon-Weds, so I wouldn't be able to even ask them about a return until Thursday. I can, however, go pick up a new tank tonight after work. My empty stand is only 24 inches long though, so it doesn't meet your minimum suggestion.

I'll have to think about this today, and see if there's a way I can fit a longer tank, or if he'll have to go in the shorter one temporarily until I can chat with the store owners. I don't like taking pets back...but...that may be my only option.

I am improving, thanks. It's slow going, and my husband will have to do the heavy lifting on the new tank, but I'm getting there. It's very frustrating...but I am getting a lot of exercise doing water changes with quart containers.
A tank that is 24 inches long will be fine for 1 paradise fish. Have lots of floating plants like Water Sprite and treat it like a Betta splendens (Siamese fighting fish).
A tank that is 24 inches long will be fine for 1 paradise fish. Have lots of floating plants like Water Sprite and treat it like a Betta splendens (Siamese fighting fish).
Thanks Colin. That's what I decided too (and I have a Betta in another tank as well, so I'm very familiar with that type of care). Fritz the Betta is also a very grumpy little fish who does not care for anyone in his domain at all (though he does put up with a Nerite, barely).

I'm pleased to say that Eddie moved into his new digs this morning (I seeded the filter from the other tank), with little fanfare, and I think the tetras (Pristilla, not Priscilla...geez) are relieved. Since I'm still limited as to how much weight I can lift, I had to have hubby shop for the aquarium with me, which means instead of the more natural 'scape I generally go for, Eddie has a pirate ship, skeleton and shiny quartz rocks in his tank, but it fits his rebel nature. He's also got a bunch of frogbit, anacharis, and hornwort both floating and planted. I'll get him some java fern and moss from another tank in the near future, and some driftwood bits this weekend. I put some catappa leaves in there for tannins for now, since I don't have any extra driftwood at the moment.

I wish I could find water wisteria around here. But, the weather's nicer, so...maybe time to order some! :)

Thanks for the help, guys. Eddie is a beautiful little curmudgeon, and I think I'll enjoy having him around, even if he was initially a mistake.

Forgive me, FF, For I have Sinned...​

I used to breed paradise fish - you have a species that has been in European tanks since at least the 1660s. Samuel Pepys mentioned them in his diary back then.

They aren't that aggressive. Like betta splendens, they can linger in small tanks for a long time, since they have a labyrinth organ to breathe with. They tolerate water pollution better than we should ever test out. Tough coolwater fish, good from close to freezing until with mid 30s C.

In the tiny tank era, they got a bad rep for destroying tankmates, but I had lots of them in large tanks, and they didn't even eat all the livebearer fry. It was the small tanks more than the behaviour of the fish themselves. They are grumpy and grouchy, but not overly aggressive.

I'd give them at least a 15 - 24 inches as suggested by @Colin_T .

As for the sinning, you've already got a paradise. You're good.
They are grumpy and grouchy, but not overly aggressive.
That makes sense - thanks! He didn't hurt any of the tetras, but he definitely wanted them where he wanted them, and not running amuck in "his" tank. That tank is around 38 gallons (36 x 12.5 x 19.5), but he was already blowing bubble nests dead center in the plant cover. I appreciate that he was apparently very happy there, tetras weren't. They've been really active all over the tank since I moved him out.

He's got a 20 gal (24in long) tank all to himself now, and he seems happy with that. It sits right next to the other tank, so he can see the other fish through his plants when he wants. I wanted a 20 gal anyways as a "just in case the plecos start fighting once they mature" failsafe, and Eddie didn't seem to take any note of the plecos in the big tank, so I'm fairly certain he'd be okay if my clown plec needs to move in with him eventually.

All's well that ends well Here's a pic of Eddie, who got some new plants and driftwood for his tank today. Such a pretty little tiger-striped guy!

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