On fishkeeping scientific facts versus myth

[OohFeeshy]

My thinking exactly LifeBear. Lol, and I mean exactly. The only difference is that I use a goldfish instead of the betta example and a german shepard instead of a doberman I also think that the minimum aquaria size for a common goldfish should be 75 gallons, the same as an oscar, as they reach a similar size and both are very messy fish. Well anyway, I don't need to say anything as others have said it for me

 

[Synirr]

andywg, I agree that it's unlikely to have much of an impact to hobbyists, but I'm sure the casual aquarium owner can observe the effects of this. Infrequent water changes combined with small water volume could (and I'm sure does) cause these chemicals to build up and stunt a fish. One of my friends has a 10 year old goldfish in a 10 gallon aquarium who has never reached his full size...

 

[andywg]

Well, we ask why people come up with the bad myths time and again, I found this site and just look at the lovely advice given by someone claiming to be an expert with 44 years experience...(logged as doug101)

BGK

I have quoted the worst part of this exchange

How big a tank for a black ghost knife fish is really a great question! How big do you want it to grow to will answer your question of how big a tank you will need.If you want your ghost to grow to a foot or bigger then you would need a minimum of a 72 gallon tank. See fish grow to the size of aquarium that they are kept in. If a fish such as a ghost knife is kept in a small tank for to long of a period he will become stunted, and when and if he ever gets to a bigger tank he might start to grow again, and may be not, till seems to be the way of most fish specially if you have more than one .They send out a hormone to the other fish in the water saying you guys dont grow and i will, but when you have lots of these hormones kicking around no one seems to grow unless you do lots of water changes.

While it has been shown that there are some hormonal growth inhibitors, I don't think keeping a fish with a max aquarium size (not wild) of 20" in a 10 gallon tank is ever going to be a good idea...