Big Fish Little Tank

[MrsE88]

I'd go with a Green Terror.....not big....but big enough. They look cool and they are aggressive. If you wanted to feed them live food they will attack it. I don't mind the oscar idea as long as you do water changes ALL the time!!!

I could only agree if it was a female. Have you seen a full grown male? They may not be as large as an Oscar, but my male at 10in+ is rather bulky. They are also very active swimmers that need room to move.
Look at these two... This was a year ago after their tank sprung a leak.

That’s the whole 4’ tank(75g) These guys were miserable for the few weeks they were in there. It was sadly the best I could do while their tank was getting resealed.

Op- As said already, it’s one thing talking numbers on here.... seeing a fish housed the way you are talking is very sad looking in person. And with some fish, such as cichlids, being housed like that can cause stress and will lead to nothing but health issues. Even if the water quality is kept up.

 

[Travis_Bickle]

Mind you, fish are always skittish/moody/miserable if put in a smaller tank after being in a larger one, obviously there's little choice temporarily if you get a leak!

Whatever you get, you'd need to put it in the tank you intend for it from the start, and ideally get a smaller one to grow on. Personally, i think Red Devil/Oscar/Jag really need 5 foot by 18 inch MIN and Green Terror / Jack Dempsey / Severum a 4 foot by 18 inch MIN.
Firemouth/Salvini and the like probably ok 3 foot by 18 inch. Larger quarters for fully grown breeding pairs.

 

[Backfromthedead]

For a 75-90 gallon, i would not put any cichlids that grow larger than 10-12". Just one fish this size would fill the tank, with limited scaping to free up swimming space.

For fish like tetras, silver dollars, piranhas, i would not exceed 6-8", as most characins are more skittish, do better in groups, and require more space imo.

 

[Rocksor]

Stick with something that has a full adult total length of 10" or less for an relatively active swimmer. Ambush barely moving predators like a gulper or 3-4 upper jaw bichirs ( no weeksii, teugelsi, or ornate) that don't move much would be fine in a 90g.

 

[Raka]

Thank you for the info for the people who understand this thread!

For those stating in your reply this fish wont be comfortable, re-read the original post...

Im looking for Ideas that hadnt occured to me of for fish I dont know about. The common is great idea right up my ally and now I have gulpers and upper jaw bichirs I can learn about that may be practical for me to keep one day.

Again I am not looking to torture a large fish.

 

[Travis_Bickle]

Thats a superb pair of Rivulatus by the way.

 

[BIG-G]

Thank you for the info for the people who understand this thread!

For those stating in your reply this fish wont be comfortable, re-read the original post...

Im looking for Ideas that hadnt occured to me of for fish I dont know about. The common is great idea right up my ally and now I have gulpers and upper jaw bichirs I can learn about that may be practical for me to keep one day.

Again I am not looking to torture a large fish.

I get what you are saying. The problem is the wording.
You want a big fish, that can comfortably live in smaller tank.

I am looking for suggestions for big fish species that can be comfortable kept in smaller tanks.

There are no big fish that can be “comfortably” kept in small tanks.

I understand that because some fish species are less active you may get away with a smaller tank than others.
I assume this is what you mean.

I would say that most people are afraid to give any advice in this direction because of the fear of a fish being stuck in a situation that may be just good enough to live, but not really thrive.

This is why most fish keepers with experience will recommend larger tanks for a species, not smaller.

 

[duanes]

I have kept a Eleotris goby in a 180gal now for about a year. Most of the time, it sits in one spot, half buried in the sand, and only moves when hungry. When I first got it, it was not quite 8". now a little over 10".
IMO to stay healthy, most cichlids need space, and need enough room, for movement, and to get exercise to remain healthy, so even the average medium size cichlid gets too big to big for a small tank, and to me Oscar's need over 100 gallons.
This type "sleeper, might work.

Video below
Goby Grab