Appropriate tank size?

[crob67]

How do you determine the appropriate tank size for a fish? The only sites that I can find that list tank sizes for fish are online retailers, and they are radically different. For instance, I looked up the "chain (chainlink) eel" echidna catenata at two different sites. Marine depot live says that it can be kept in a 30g tank, and LiveAquaria says it needs a 125. I know setup, filtration, tankmates, etc. make a difference on how big a tank needs to be, but how do I get a general idea?

[Ping]

I myself trust Liveaquaira over many other sites. I am not familiar with the eel you give as an example. I would presume that the 125 rating is for a fully grown pet and a 30 would be for a juvenile.

As for a general idea, I could put a tang in a 55 but it wont thrive as well as it would a larger tank.

[OldSalty]

Boy, that is the key isn't it Ping, SURVIVE AND THRIVE. Crob, your are to be comended, We need more folks like you guys, that look before you leap. Can you believe there are the ones who keep a SHARK in a 55.

[crob67]

Thanks guys...I'm trying to decide how to stock a 45 cube and have researching a lot of different fish...It gets a little overwhelming when different sites give completely different info