is it true that blue tangs need a minimum of 70 gal??

well its an old wise tale! lol I heard that from a LFS employee so it must be true.. ok Ive read most fish only grow 65-75% of their max size in average size 20g-100g aquariums and same fish in ocean will grow to full sized length.. maybe thats what it is.. never the less, make sense to me.

 

That sounds true, that fish don't grow to their full potential in tanks and I guess its because in the wild they can eat as much as they like, get more exercise etc

That being said, I still wouldn't keep an adult regal (even at 8"-9") in a 70US gallon. They are so active I would feel mean.

 

absolutly.. I'd say 4-5" long fish in a 55-70g tank.. after that its time to upgrade or trade fish in..

 

hrm that's interesting but i kind of think it doesn't matter what size the tang is.. whether it's 2 inches or 5 inches, the amount of swimming room they need from one side to the other to enjoy themselves woudln't be much of a difference.. it's kind of like, if you were 10 years old, and you were 25 years old, a small place is a small place.. wouldn't make much of a difference.. same kind of concept in my opinion..

 

I've read with tangs, it's not so much their physical size that determines the necessary tank size, because they are so active. There are lots of fish that get to only 3 inches, but the recommended aquarium size is 90 gallons! It's because of the activity level.

 

with that being said, hte fish would have the same activity in a 40 gallon as in a 90 gallon. they will still swim just as much just not as lon in one path. just a thought.

 

Yes, but it's different. It's not as much space. Which is why there are minimum tank sizes. Using that logic then, we could have 20 gallon tanks with 10" long fish, because they could just swim back and forth all day being active.

 

Yeah, that is kinda true.

Given enough time, and if it wouldn't die of obesity, a regal tang will grow to it's 10" max size, even in a 55g tank. Now the smaller tank will not allow it to exercise like it would in a bigger tank, so taking a 4" regal from a 55g where it would be getting too big for that tank and putting it in a 200g tank it will grow much faster in the bigger tank due to being allowed to exercise more.

I personally wouldn't put a blue tang in anything less than 120g, but a friend I have that has a pretty large regal (about 8")in his 120g is probably at the max size that fish should be in his tank. You can tell that tang would be happier in a bigger tank. like mine LOL

Also, you can tell when a fish needs a bigger tank and more room to swim. they get bored and go on the exact same path to make "laps". Kinda like bears or wolves in a smaller cage at a zoo. They get bored.

 

ok, i thought by the 3 inch fish you meant something else. i agree with you.