Final decision

PiranhaFan

Feeder Fish
MFK Member
Apr 27, 2017
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Hello, I have decided to go with a black piranha. I have a tank that is over 100 gallons, I am not sure how many gallons it can hold, but it is 6 feet long, 22-24 inches tall, and 18 inches wide. I was wondering if this it big enough to raise a black piranha for it's whole entire life. If it isn't I may be forced to change my mind. If there is anything you would like to tell a possible new black piranha owner, please do. I just need the minimum tank dimensions now to make the full decision. I have also noticed that sometimes full grown black piranhas develop bumps on their chin, or in other places on their body, I was wondering what this might be? The more information provided, the better. Thank you.
 
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heavyhitter

Piranha
MFK Member
Mar 17, 2008
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Sound like you have a standard 125g tank. That tank is too for a full grown full sized Rhombus. That said if you get it small it will be many many years before that tank is out grown. And thats IF it ever reaches its full potential.
Bumps on some fishes "chins" are the result of hitting the glass repeatedly.
 

PiranhaFan

Feeder Fish
MFK Member
Apr 27, 2017
16
7
3
26
Sound like you have a standard 125g tank. That tank is too for a full grown full sized Rhombus. That said if you get it small it will be many many years before that tank is out grown. And thats IF it ever reaches its full potential.
Bumps on some fishes "chins" are the result of hitting the glass repeatedly.
What would you recommend for it's whole life, also how long could the 125gallon last him?
 

heavyhitter

Piranha
MFK Member
Mar 17, 2008
600
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A 180+ would be better. After 6" or so the growth slows down considerably, like 1/2 to 1 inch a year. A small one a 125 would easily last 5-7+ years.
 

Yohanon

Plecostomus
MFK Member
Oct 11, 2016
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Hello, I have decided to go with a black piranha. I have a tank that is over 100 gallons, I am not sure how many gallons it can hold, but it is 6 feet long, 22-24 inches tall, and 18 inches wide. I was wondering if this it big enough to raise a black piranha for it's whole entire life. If it isn't I may be forced to change my mind. If there is anything you would like to tell a possible new black piranha owner, please do. I just need the minimum tank dimensions now to make the full decision. I have also noticed that sometimes full grown black piranhas develop bumps on their chin, or in other places on their body, I was wondering what this might be? The more information provided, the better. Thank you.
It would be big enough for a few years. Rhoms get big, but grow slowly. Rule of thumb, about 6" their first year, then about an inch per year after that, maxing out at about 18". To keep one for life, (they can live 20-30 years) I would consider a 150 or a 180.
 

nzafi

Goliath Tigerfish
MFK Member
Mar 14, 2008
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You're fine with a 125g. No and I mean no one has grown a small rhom past 11-12in. Those that got them past 12inch imported them around 9-10in and even then I've never heard of one past 13in. Many folks go even smaller at 75g.

I kept my rhom for 17 years and he stopped at 10in. After hitting 5in he averaged 1/2in a year before stopping. Another member here had a rhom for 34 years and it stopped at 12in. All the 14-17in rhom out there are imported at that size. Even then it varies on the type of rhom.
 
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heavyhitter

Piranha
MFK Member
Mar 17, 2008
600
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Nebraska
You're fine with a 125g. No and I mean no one has grown a small rhom past 11-12in. Those that got them past 12inch imported them around 9-10in and even then I've never heard of one past 13in. Many folks go even smaller at 75g.

I kept my rhom for 17 years and he stopped at 10in. After hitting 5in he averaged 1/2in a year before stopping. Another member here had a rhom for 34 years and it stopped at 12in. All the 14-17in rhom out there are imported at that size. Even then it varies on the type of rhom.
That is simply not true. There is a member on here, and he also post Youtube videos for his 18" Rhom he grew out. Its rather presumptuous to say NO one has done it. Granted large specimens are indeed very rare in the hobby I will give you that.

Tank recommendations are also based on trying to humanely keep a fish in a suitable habitat. Keeping any sizeable predatory fish in a small tank is just cruel. Large water volume also help diluting waste these fish make keeping nitrate to down to a manageable level between water changes.

These fish expel ammonia from breathing, urinate and crap all in their home. Keeping a wide bodied 12-13" fish in a 75 gallon or smaller is irresponsible at best.

What would you rather live in, trapped your whole life living with your waste until some cleaned it? A closet? A bedroom? A house? A mansion? A shopping mall?

Bigger is always better for predatory fish.
 

nzafi

Goliath Tigerfish
MFK Member
Mar 14, 2008
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heavyhitter heavyhitter Do you have links to the youtube videos or know the names. I have been on predatory forums and piranha forums back until '99. I have spoken to many of the folks that have been keeping piranhas for 30+ years and were viewed as the piranha gods for North America and Europe. Most of them state what I said about growth to 12in. The best case scenario I heard of was someone growing a freshly imported 10in rhom to 13in and then it stopped. Most of us have also never seen a rhom truly measured at 18in. Many folks have claimed but when they put a ruler the largest has been 17in.

Don't mean to argue, but I would really love to see that as piranhas started my passion 18 years ago and I would love to see it and learn what they did to be successful.
 

heavyhitter

Piranha
MFK Member
Mar 17, 2008
600
129
76
Nebraska
heavyhitter heavyhitter Do you have links to the youtube videos or know the names. I have been on predatory forums and piranha forums back until '99. I have spoken to many of the folks that have been keeping piranhas for 30+ years and were viewed as the piranha gods for North America and Europe. Most of them state what I said about growth to 12in. The best case scenario I heard of was someone growing a freshly imported 10in rhom to 13in and then it stopped. Most of us have also never seen a rhom truly measured at 18in. Many folks have claimed but when they put a ruler the largest has been 17in.

Don't mean to argue, but I would really love to see that as piranhas started my passion 18 years ago and I would love to see it and learn what they did to be successful.
I don't know at what size Steve acquired this beast but here is a monster

Im at work and I cant find the videos but there is member in this forum that has a huge Rhom, its in a 125 gallon and his tail and snout pretty much touch the class on both ends when his facing forward. Its is so massive it makes the 125 look tiny, the fish is also very active and more aggressive than the one above. I recall he was trying to get a 180 for it.
 

nzafi

Goliath Tigerfish
MFK Member
Mar 14, 2008
2,172
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I remember that rhom. It was purchased at close to that size, it was not grown in captivity. Aquascape brought in a "18in" that I saw in person before it was sold to someone not on these forums. That was massive. Another member on here states his is 18.5in and I saw that in person but cannot verify it was truly 18in because we did not use a ruler. It was housed in a 265g and was simply massive.

A standard 125g is 18in wide exterior and interior dimensions is probably like 17.5in or slightly less. Unless they had a custom tank, that rhom would have been less than 18in.
 
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