[OfAmethyst]

What do you think would be the most natural setup for piranhas in terms of dimension? I figured if we can figure out more about the fish we can reduce stresses that they wouldn't be used to in the wild. These are some ideas I've had but, I'd like some experienced opinions and some new facts. I don't see the point of having fish tanks if we can't make the fish happy too. (Please be constructive with the criticism as we're here to learn).

Things I'm taking into consideration:
-Each tank has their pros and cons
-Assume the tank is large enough for multiple piranhas
-Piranha's age
-Piranha's age relative to other piranhas in tank
-Floating plants for head cover
-Plants in general
-Caves for security/breeding
-Varied diet (sinking, floating, veggies, live, frozen, pellets, etc)
-They're considered top feeders because of their mouth shape going up
-These guy's are considered shy but exhibit aggressive feeding habits
-Anything with a brain also needs to be exercised mentally/physically or it can grow bored, depressed, aggressive, sick, etc.

Taller tanks...
-would let them dart up for floating food and dart back safely without as much worry of hitting something or hurting themselves
--does not give much exercise room with decor
--lacks ground space/vertical movement area

Longer tanks...
-would give them the option to swim long distances and get some exercise.
-Gives option to feed on one end of the tank
--harder to filter in some cases

Breeder tanks...
-(wave maker) can help circulate flow better maybe
-(wave makers) can also reduce need for longer space
-can create more natural ground space with varying levels
-They have plenty of turn space everywhere and don't feel trapped
--would be harder to catch fish if necessary

 

[Ægir]

This has been discussed a few times, and there is lots of reading on the subject. Basically any stable environment is best, most fish are in captivity their entire life and dont remember their natural habitat. Decor, lighting etc is up to the owner and the fish will acclimate to it. Some fish will not tolerate plants, some will... same can be said about tank-mates and other fish.

As for tank size and flow, I have always leaned towards a bigger footprint / length and stayed away from taller tanks. I was going to build a tank with a constant linear flow (from one end to the other) to replicate a river, but never got around to it. All of my tanks have always had around 10x filtration flow and another 10-15x in powerheads.

Wavemakers really have no use in a freshwater tank.

 

[timmy]

I had RB spawn in a 125 gallon 6ft tank that was part of a shoal...

 

[TheTyeMan]

I always used a 72 bow front to put my babies in. Mostly because it's what I had kicking around. I liked the length so the babies could spread out. Smaller tanks I usually ended up with 20-30 make it to dime size. The 72 I pretty much always had 100+ make it.