BIG FISH: Swimming Space or Water Volume?

[MnFish1]

Well I'm not saying that a certain size tank won't work for a certain creature, but I know there is a higher chance of stress in a tank with less swimming space. Like in Jay Hemdal's post if your tank has a height of 12" or more than it won't make a difference after that as fish will spend most of their time swimming 2 dimensionally. I'm just stating what I have personally seen and what experts have stated already.

I think the aquascaping has a great deal to do with how and where the fish swims. If you have a tank which has 2/3 of the top of the tank 'open water' Lets say you have a 3 foot tall tank, I agree that the fish will likely congregate where there are hiding places available if needed - as compared to swimming in open water. On the other hand - if you have a wall of rock covering the full back of the tank - in my experience - the fish will utilize all of the space. I did not see Jay's post - I will look at it. In my tank - though in general the fish tend to have their 'areas' they swim in I have never seen them swim only in the bottom 12 inches of the tank.

 

[Aspect]

Wronggg atleast in my case anyway. Like I said in previous post mine love using the whole height of the tank. Infact it got me thinking why people don't have taller tanks lol. Noone can state fact about what a fish will do in anyone elses tank experts don't know anything because our tanks aren't the ocean and they don't have every fish in every aquarium to compare.

I never said that in every case, a fish very well could adapt and be fine, but I'm looking at a majority. Experts are experts for a reason and they have analytics/data to prove their points. You should read Jay Hemdal's article:

Estimating the Need for Swimming Space for Aquarium Fishes​

 

[Treefer32]

My tank is 6ft by 3ft wide by 31" tall. Now, my tangs don't use the vertical as much as I would like, but, my Creole (10"+ fish) use the vertical as much as the horizontal. They are constantly splashing water out of the tank with their tails. I don't know why they do this, but, I come down every morning with water marks on the glass from water splashed over the rim. I've gotten splashed when walking by the back of the tank (which is painted) by the Creole Anthias. Why they do this, I don't know. But, they use all space of the tank, including hanging out under my giant toad stool during the day to get away from when the lights are brightest.

So, my question is not so much volume or size, but does the tank provide the fish things to do. When I was setting up my powerheads and tank circulation, I wasn't planning for fish entertainment. I was planning for the best methods for keeping organics suspended in the water column so they eventually make it to the sump. I placed 2 gyres on each end mounted, at the surface for greatest aeration and flow. I also put 2 MP40s positioned on the back glass pushing forward to get water circulated from the rear of the tank to the front, and I positioned them both in tunnels so the water would have a path.

Little did I know I had installed two treadmills for fish entertainment and exercise. . . Fast forward 4 years... My tangs especially, even some of the angel fish, will fight over the tunnels every morning to swim against the current of the MP40s. My massive Caribbean Blue tang (10-12" in diameter) uses the tunnels the most to exercise. My Mimic and black tang will take turns after him. They line up in the morning and swim for anywhere from 5-10 minute intervals. Each taking a turn. Then, they'll go about their day and come back every little bit to swim again against the current. . .

It may be a sign that the tank is too small for the Caribbean blue tang.. At the same time, they're finding ways to keep exercising and release aggression. . I agree with others that caves and nooks and crannies are just as important as size of tank. Hiding spots can make smaller tanks more tolerable. I advocate that powerheads strategically positioned close enough to the bottom with a sheltered path for fish to swim against the current is also important.

I was amazed by the behavior my tangs exhibited almost to the point of fighting over the powerhead flows.

 

[DeniseAndy]

Depends on the big fish we are talking about. I think most need both. However, some like more up and down and some like more distance, some like more area. I say if you are keeping large fish, you need both good long runs, deep tanks, lots of volume too.

 

[uhgster1]

I voted other. I think that if you are going to keep a large sedentary fish (lion fish, stone fish, scorpion fish, anglers, some groupers), then the water volume is going to be more important than swimming space. They don’t swim around much but because of their size can pollute a smaller volume of water quickly. Common sense tells you that most pelagic fish and grazers need swimming room regardless of their size. We can’t keep (most of us anyway) 5000 gallon tanks to really keep them happy so it comes down to what you’re comfortable keeping. I personally hate the aesthetics of them but circular tanks are the only ones that make sense for large swimmers. Kind of like a hamster wheel for fish that need to constantly swim.

 

[WRB]

I have a 6ft long 125, Fowlr 3 large tangs,1 large Koran, a Fox face and 2 Triggers. Most the time they don't know half the tank is even there. They're like dogs with the zoomies and they decided the track is only 3 feet long.

 

[Stefaan F]

I have a 11'x4'x3'2".
I noticed that this height really makes the fish swim in another dimension.
Stress and fighting is greatly reduced not only because of aquarium size, but also because the fish can swim away in any direction.
A bit strange when you think about it, but in a lower or narrower tank escaping threats means you have only a few options, or if the agressor plays it well, you need to pass him to escape.
In a high and wide tank, the possibility to escape in any direction (up/down/left/rigt/front/back) makes it impossible to corner a fish. Resulting in the fish being less worried about escaping and being in front all the time without agression.
Really, if I put in a new fish there is a 90% chance the others just come and watch the new one closely and don't show agression.
Even fish like my pomacanthus navarchus who has the reputation of hiding is visible all the time in my aquarium. The guy I bought him from almost never saw him.

This is a luxury to have that size tank, but size really has its benefits.
With smaller tanks I would prefer wide and deep, not tall because I would want to optimise 2 dimensions rather than having 3 suboptimal dimensions.
I would never take a very long, narrow and low tank (like 6'x1.5'x1.5') as it is way harder for the fish to escape.