fish inches

[sharkbait]

I don't really buy the whole "fish inch" idea. ie 1 fish inch per gallon

Some fish are small and screawney whilst others for the same length have much more body mass.
Also it seems that some fish are "dirtier" than others. I assume its to do with the amount of food they consume???

what do you think folks?

Does anyone have a more sophisticated system?

Or have I just invented a whole new branch of mathematics called fish algebra?

PS does this mean I can buy some more cardinals

 

[MAM]

that rule is basically a guideline for beginners. youre right, it really varies by the space needs of the fish, whether they are part of a school or not, bottom or top or middle dweller. how well they get along with other fish/territorial needs, etc. and a big factor is the amount of filtration you have. the more you have, you can have more fish in many cases. its also about how much room the fish have to move. as i was talking to another member about, he had fish that grows up to six inches. he didn't understand how he could have 6 1-inch neons fine in 10 gal but not one 6 inch fish (namely one that doesn't have that lovely bendy motion when it swims). i told him that six little separate fish can turn around and move quite well in 10 gal of water but a six inch fish wouldn' have nearly as much space to turn around or swim properly when you factor in plants and decor and the fact that the average 10 gal tank is only 12 inches wide.
there's really not set way to determine what will or will not fit other tahn using good common sense. depending on what all you have, the size of the tank (if its under 10 gal, probably not), and how good your filter is, maybe you could get more cardinals.
or you could go and lock yourself in a room and drive yourself batty trying to come up with a proper fish algebra for every kind of fish community available

 

[rsz]

i think we only have this rule for beginners, who otherwise might completely fill their tank, so that fish have no swimming space. I don't follow it too well . a fish could be very long, but only a few mm's wide . or only a few cm's long, but produces alot of waste.

i think that so long as your bacteria in the filter and gravel can cope, then the amount of fish you have is ok.

i used to have a website saved in my favourites with an interesting method for stocking a tank, where you worked out your surface area, but i cant find it (i'll keep looking )

 

[Paradise_Gourami]

Volume in US gallons/type Max. inches of fish based on
1" of fish per 12 sq." of surface area

2.5 6"
5 10"
10 15"
15 24"
15high 15"
20high 24"
20long 30"
25 24"
29 30"
30 36"
30breeder 54"
33 52"
37 30"
38 36"
40breeder 54"
40long 52"
45 36"
50 54"
55 52"

I dont know if they did the math right bu the sight is
http/www.thetropicaltank.co.uk/tanks-us.htm

 

[rsz]

that's an interesting method paradise_gourami - i think using that method, my tank isn't overstocked!! woohoo!

 

[Paradise_Gourami]

And when you measure the length of fish you dont count the tailfin in our measurements.

 

[yhbae]

The weight of the fish matters more than the total length of the fish.
Also, the water surface area of the tank matters more than the total volume of the tank.

I've been trying to come up with the general formula to do this but unfortunately there isn't. I ended up listing all the fishes I may want to get, and one by one, I assign what I call "fish factor" which is essentially "how fat the fish is". When you take this into account, it works out quite well.

I've been verifying the formular/sheet for a while by testing it against the questions that comes across every once in a while with the topic "Am I overstocked?" and so far, it seems to work quite well.

12 inch oscar is not the same as twelve 1 inch cardinal tetra since I assign Oscar with a fish factor 3, while cardinal tetra only gets 0.7. So In reality, 12 inch Oscar is at least 4 times dirtier than twelve 1 inch cardinals.

Of course, I could still be off with the fish factors, but I am refining them over time and they seem pretty good now...

This obviously doesn't take into account aggressions and territories for some species which could limit even further.

 

[sharkbait]

I like the fish factor idea.
I can figure out fairly easily the relative body mass.
More difficult is the "dirty"factor.
I am told goldfish produce more waste.
Any other fish on the "dirty fish" list??

 

[wuvmybetta]

platies and guppies are pretty dirty ,big time poopers


I think the inch rule is a good one but,as said, it really requires common sense also...I have 14 kuhli loaches in a 42 with several other fish, the loaches are teeny tiny and rarely seen but according to the "rule" if their max size is 3" they'd require that entire 42 to themselves

 

[ketyana]

The inch per gallon (or 1/2cm per litre which is sometimes used cause well decimelation started in 1971 in the uk and I didnt start school until 1981 and I have little idea what an inch or a gallon looks like (feet and pints I kind of get!!!)) is recommended to beginners, but it is worth pointing out the most popular (maybe not the best I do not know but the most widely sold) magazine for fish keeping in the uk then goes on to recommended that this can increase to 2" per gallon after the first 6months

see here under stocking

 

[Moe]

Someone posted this method a while back. It made sense to me. Now it is the method that I use. I do have the filtration to back it up though. I would not stock a tank this heavily without mega filtration. It's pretty long but here it is:

A Stocking Method That Works
You've all heard the "one inch of fish per gallon" rule of thumb, but every tank is different in terms of gas exchange and volume, and surface area. So why hasn't anyone come up with an accurate stocking method that fits your tank? Well they have. I rented a book out from the library called "The Complete Fishkeeper," by Joseph S. Levin, and it had a stocking method that worked great!!! This book is hard to find and expensive, so i'll tell you how it's done.
If you can add, subtract, multiply, divide, and own a calculator, it should pose no problems.
Multiply the length and width of your aquarium in inches to get your tank's surface area. Let's say that the tanks measurements are 24" by 12", a standard 20 gallon, you'd get 288sq.in. Now before you do anything else, i should say that you should have a list of fish that you want to get, and have their maximum adult lengths at hand. Always start off with a plan, trust me.
The longer the fish is, the thicker the body is, and the heavier it's bio-load in the tank is. So It's not fair to keep 1 20-inch fish in a 20 gallon aquarium, and a 20 gallon stalked with 10 2-inch fish looks pretty empty, so the stocking rule will change for each fish size category. For fish upto 2 inches, 6sq.inches of surface area will be needed for each inch of fish body. For fish between 2-4inches, 9sq.inches of surface area will be needed for each inch of fish body. And finally, for fish between 5" and up, but not too long, 12sq.inches of surface area will be needed for each inch of fish body.
This may seem complicated, but it's not. Let's say that in this 20 gallon tank, you'd like to keep 6 Black Neons. At 1 1/2 inches per fish, it would fall into the "up to 2 inch" category, demanding 6sq.inches of surface area per inch of fish body. Now simply multiply the fishes length by the required surface area per inch of fish, and you get the total surface area that a fish of this size needs, which, in this case comes out to 9sq.inches of surface area per Black Neon (1.5 X 6sq.inches=9sq.inches). I want 6 Black Neons so i multiply 9sq.inches by 6 (the number of fish i want) and get a total or 54sq.inches of surface area for 6 Blach Neons (9sq.inches X 6=54sq.inches). I now subtract this total from the total surface area and find out that i can keep 6 Black Neons in my tank and have 234sq.inches of available surface area in my tank (288sq.in - 54sq.in=234sq.in).

 

[rsz]

Someone posted this method a while back. It made sense to me. Now it is the method that I use. I do have the filtration to back it up though. I would not stock a tank this heavily without mega filtration. It's pretty long but here it is:

A Stocking Method That Works
You've all heard the "one inch of fish per gallon" rule of thumb, but every tank is different in terms of gas exchange and volume, and surface area. So why hasn't anyone come up with an accurate stocking method that fits your tank? Well they have. I rented a book out from the library called "The Complete Fishkeeper," by Joseph S. Levin, and it had a stocking method that worked great!!! This book is hard to find and expensive, so i'll tell you how it's done.
If you can add, subtract, multiply, divide, and own a calculator, it should pose no problems.
Multiply the length and width of your aquarium in inches to get your tank's surface area. Let's say that the tanks measurements are 24" by 12", a standard 20 gallon, you'd get 288sq.in. Now before you do anything else, i should say that you should have a list of fish that you want to get, and have their maximum adult lengths at hand. Always start off with a plan, trust me.
The longer the fish is, the thicker the body is, and the heavier it's bio-load in the tank is. So It's not fair to keep 1 20-inch fish in a 20 gallon aquarium, and a 20 gallon stalked with 10 2-inch fish looks pretty empty, so the stocking rule will change for each fish size category. For fish upto 2 inches, 6sq.inches of surface area will be needed for each inch of fish body. For fish between 2-4inches, 9sq.inches of surface area will be needed for each inch of fish body. And finally, for fish between 5" and up, but not too long, 12sq.inches of surface area will be needed for each inch of fish body.
This may seem complicated, but it's not. Let's say that in this 20 gallon tank, you'd like to keep 6 Black Neons. At 1 1/2 inches per fish, it would fall into the "up to 2 inch" category, demanding 6sq.inches of surface area per inch of fish body. Now simply multiply the fishes length by the required surface area per inch of fish, and you get the total surface area that a fish of this size needs, which, in this case comes out to 9sq.inches of surface area per Black Neon (1.5 X 6sq.inches=9sq.inches). I want 6 Black Neons so i multiply 9sq.inches by 6 (the number of fish i want) and get a total or 54sq.inches of surface area for 6 Blach Neons (9sq.inches X 6=54sq.inches). I now subtract this total from the total surface area and find out that i can keep 6 Black Neons in my tank and have 234sq.inches of available surface area in my tank (288sq.in - 54sq.in=234sq.in).

i posted something like that once, i'm sure i did what website is it off? it seems like a really good technique in my mind

 

[yhbae]

I like the fish factor idea.
I can figure out fairly easily the relative body mass.
More difficult is the "dirty"factor.
I am told goldfish produce more waste.
Any other fish on the "dirty fish" list??

Livebearers in general produce more waste relative to their weight. So I assign factor of 2.0 for them. Pl*cos are nortorious for being dirty, so I give them 3.0. Most of the tetras get 1.0 except for thin ones like neons and cardinals which get 0.7. I give 1.0 for the cories even though they are fat since they don't add much to the bioload. Cichlids in general are dirty as well even if you take into account their size.

 

[yhbae]

Someone posted this method a while back. It made sense to me. Now it is the method that I use. I do have the filtration to back it up though. I would not stock a tank this heavily without mega filtration. It's pretty long but here it is:

A Stocking Method That Works
You've all heard the "one inch of fish per gallon" rule of thumb, but every tank is different in terms of gas exchange and volume, and surface area. So why hasn't anyone come up with an accurate stocking method that fits your tank? Well they have. I rented a book out from the library called "The Complete Fishkeeper," by Joseph S. Levin, and it had a stocking method that worked great!!! This book is hard to find and expensive, so i'll tell you how it's done.
If you can add, subtract, multiply, divide, and own a calculator, it should pose no problems.
Multiply the length and width of your aquarium in inches to get your tank's surface area. Let's say that the tanks measurements are 24" by 12", a standard 20 gallon, you'd get 288sq.in. Now before you do anything else, i should say that you should have a list of fish that you want to get, and have their maximum adult lengths at hand. Always start off with a plan, trust me.
The longer the fish is, the thicker the body is, and the heavier it's bio-load in the tank is. So It's not fair to keep 1 20-inch fish in a 20 gallon aquarium, and a 20 gallon stalked with 10 2-inch fish looks pretty empty, so the stocking rule will change for each fish size category. For fish upto 2 inches, 6sq.inches of surface area will be needed for each inch of fish body. For fish between 2-4inches, 9sq.inches of surface area will be needed for each inch of fish body. And finally, for fish between 5" and up, but not too long, 12sq.inches of surface area will be needed for each inch of fish body.
This may seem complicated, but it's not. Let's say that in this 20 gallon tank, you'd like to keep 6 Black Neons. At 1 1/2 inches per fish, it would fall into the "up to 2 inch" category, demanding 6sq.inches of surface area per inch of fish body. Now simply multiply the fishes length by the required surface area per inch of fish, and you get the total surface area that a fish of this size needs, which, in this case comes out to 9sq.inches of surface area per Black Neon (1.5 X 6sq.inches=9sq.inches). I want 6 Black Neons so i multiply 9sq.inches by 6 (the number of fish i want) and get a total or 54sq.inches of surface area for 6 Blach Neons (9sq.inches X 6=54sq.inches). I now subtract this total from the total surface area and find out that i can keep 6 Black Neons in my tank and have 234sq.inches of available surface area in my tank (288sq.in - 54sq.in=234sq.in).

This almost works since this is what I started with, but can you say 1.5 inch platy produces the same waste as 1.5 inch Cardinal Tetra? Not really. This is why I started with this "fish factor" thing...

In my tank, I do have 1.5 inch harlequin rasbora and 1.5 inch platy. There's not even a comparison which eats more and which produces more waste...

 

[Bol]

The simpler a "rule" gets, the broader its scope, and invariably, the less accurate it gets.

There are so many other factors involved that I think the 1"/gal rule is probably pretty good for beginners, mainly for this reason: it tends to yield lower stocking levels than other calculations (edit: assuming you have a 'standard' shaped tank, and especially not a very tall one).

Now, I know this isn't the thing that fishkeepers (myself included ) want to hear, but after all, this guideline is meant for beginners, and until you get a "feel" for your tank, it is probably better to go a little light on the fish load, in my opinion.

Although I'm pretty new to aquaria, it quickly dawned on me that it seems a lot like other things, like outdoor gardening ... there are so many variables in any given situation that what works for some people doesn't work for others. There are more guidelines than rules.