Effective tank size

[hwttdz1]

So just looking at various tanks I have started to wonder about how much space various fish need. For example commonly cited on this board is tangs need 6 feet of length to be happy and healthy. How would a tang do in a tank that was 5 foot by 5 foot? Or 4' x 4'? 4' x 4' x 25" is 240 gallons, which I would think would be sufficient for some of the larger fish. I guess my question is what determines the effective tank size of a tank? How would this tank compare to the more standard sizes? I would think that additional depth beyond 2 feet diminishes quickly in value.

 

[autofreak44]

there is no real way to determine the effective size of a tank, it is a lot more guess work and rough estimation. i think that tank would be fine for a tang because even though they dont have a 6ft straight shot they still have plenty of room to swim and maneuver so i think it should be ok for some yellow tangs... this is an interesting tank size... i would like to see some pics if your project comes together

 

[lesleybird]

I think if you have not purchased a tank yet and want to get some of the faster swimming fish like tangs that they would be happier if they had a six foot length to swim back and forth in a straight shot. You could keep them in a shorter tank, but why if you are going to spend the money for a large tank anyway? I just upgraded from a 4 foot tank to a 6 foot by 2 foot tank and the fish really like the length. Lesley

 

[hwttdz1]

You think the 90 degree bend is too much and they would not be ok with swimming in a "circle" about the perimeter?