How are minimum tank sizes determined?

[guidedbyechoes]

I was wondering if there is a formula. I understand when they are standard sizes that certain fish need x amount of leg room and that makes sense. I'm looking at finding a 75 long. It's basically the same specs as a 40 gallon breeder height and width wise. It is 6ft long which I prefer longer and wider tanks to higher.

I know cubes are a different story. I'm not looking to keep any tangs. I'm more concerned with wrasse. 4 ft was barely long enough when I had my malenuras. I'm planning for a midas being the longest fish. Just wondering on the general consensus.

 

[Oscaror]

I was wondering if there is a formula. I understand when they are standard sizes that certain fish need x amount of leg room and that makes sense. I'm looking at finding a 75 long. It's basically the same specs as a 40 gallon breeder height and width wise. It is 6ft long which I prefer longer and wider tanks to higher.

I know cubes are a different story. I'm not looking to keep any tangs. I'm more concerned with wrasse. 4 ft was barely long enough when I had my malenuras. I'm planning for a midas being the longest fish. Just wondering on the general consensus.

They're just something someone came up with that has been repeated around, I'd listen to them though.

 

[Jacked Reefer]

What kind of wrasses are you wanting to get? I feel like most reef safe wrasses would be good in a 6 foot tank. and smaller tangs like kole and tomini would be too. I dont base my stocking on volume i base it off of the dimensions on the tank. if its an active torpedo shaped fish, shallow tanks work perfect. if its a taller active fish like sailfin tanks. then tall and long.

 

[ca1ore]

They're just something someone came up with that has been repeated around.

Yes .... and no. Depends a bit on where you look. Some are based off anecdotal reports from experienced hobbyists about what worked and what didn’t work. Others may be a WAG from a particular vendor. I think if one looks hard enough an accommodating answer can be found.

 

[guidedbyechoes]

What kind of wrasses are you wanting to get? I feel like most reef safe wrasses would be good in a 6 foot tank. and smaller tangs like kole and tomini would be too. I dont base my stocking on volume i base it off of the dimensions on the tank. if its an active torpedo shaped fish, shallow tanks work perfect. if its a taller active fish like sailfin tanks. then tall and long.

The fish I am considering are:

Mollies
Midas Blenny
Royal Gramma
Bangaii Cardinal
Coral Beauty
Cirrhilabrus lineatus
Carpenter's Flasher Wrasse
Melanuras wrasse
Lyretail anthias

 

[Jacked Reefer]

How many lyretail anthias? The mollies may out compete other more timid fish for food. You better be planning some hardcore filtration depending on the number of each fish.

 

[guidedbyechoes]

How many lyretail anthias? The mollies may out compete other more timid fish for food. You better be planning some hardcore filtration depending on the number of each fish.

I'm thinking a trio. Mollies would be easier of the two groups to keep. These are just fish I'm looking into. Not a stocking list.

 

[Gareth elliott]

All seem ok for a 75g.

As far as where they get the numbers, dwarf angels in the wild hold a territory about the foot print of a 55 gallon. Some of the larger ones like a lemon peel its a bit larger. But also works with other small fish and how much territory they hold in the wild. Take a fire fish. They will rarely swim in any system more than 10” in any direction from their hole.

Some larger fish they are estimates. When a shark or ray says 300+ they mean a really large system.

On the freshwater side i am glad to not see red tail catfish for sale in awhile, they do not fit in any size aquarium at full size.

 

[Jacked Reefer]

All are great for that size than

 

[ca1ore]

Lyretails get quite large and are swimmers; I’d not put them in a 75 .... no matter the length.

 

[guidedbyechoes]

Lyretails get quite large and are swimmers; I’d not put them in a 75 .... no matter the length.

Yeah I could probably just get more wrasse if I dont get them lol

 

[Gareth elliott]

Could also do something like a trio of scissor tail dartfish will get the group of fish without the size or swimming behavior.

 

[sghera64]

I was wondering if there is a formula. I understand when they are standard sizes that certain fish need x amount of leg room and that makes sense. I'm looking at finding a 75 long. It's basically the same specs as a 40 gallon breeder height and width wise. It is 6ft long which I prefer longer and wider tanks to higher.

I know cubes are a different story. I'm not looking to keep any tangs. I'm more concerned with wrasse. 4 ft was barely long enough when I had my malenuras. I'm planning for a midas being the longest fish. Just wondering on the general consensus.

I believe “they” use a . . .

. . . Wait for it. . .

. . . Fish “poll”. (They ask the fish)

Get it? A little voting season humor.

 

[cojo8888]

I would choose tank 1. Long 2. Depth 3. Height in order... isn't 6ft is good enough for most of the fish unless you want giant unicorn tang or sharks I'm confused that ur worrying about wrasse

 

[reefwiser]

It is based off of how fish swim and their behavior in various size tanks thru the years. Many fish require a good amount of space as they are always swimming around a tank and the more room you give them the less agitation they are under. Many small fish do not swim around but stay in one area constantly during the day so they need hiding spots and such to keep them stress free.

 

[guidedbyechoes]

I would choose tank 1. Long 2. Depth 3. Height in order... isn't 6ft is good enough for most of the fish unless you want giant unicorn tang or sharks I'm confused that ur worrying about wrasse

Recommendations are usually for standard sizes. I know it is discouraged keeping certain fish in cubes because of swimming needs. The 75 long I am looking into, trades the vertical space for length. I was just wondering how things were calculated because wrasse are active swimmers they will have more legnth but less vertical space to swim in this tank. I'm trying to determine if they will try to occupy the same area and that would lead to aggression. The Melanurus being my favorite fish I would just keep it if I cant keep the others. I also wouldnt want to have the lineatus being stressed to death since its the most expensive fish on my stocking list.

 

[John Neuzil]

I think they are based on what humans "think" fish need or want. Little science is involved.

 

[guidedbyechoes]

I think they are based on what humans "think" fish need or want. Little science is involved.

It could very well be arbitrary. Sort of like stocking number. I try to plan on a lighter load. I've seen people have 11 2-3 in fish in a 32 gallon. I had 4 fish in my 55 of similar length.