1" = 1 gallon?

[Andi]

Ok I've read in several places that 1" of a fish should occupy 1 gallon of water.

My current 10g hex has 2 silver dollars (2 x4), 4 pristella tetras (4 x 1), 1 golden barb (2) and 8 guppies 8 x 1.5). I plan to transfer these to a 40 gall bow front and currently have 5 pristellas in there helping to cycle the tank. I would like to add a shoal of 25+ neon/green tetras and some clown loach (or similar)

The 1" to 1 gallon rule has obviously been broken in my hex (26" fish /10gall). All fish seem happy

My question is simply how does this rule work? Is 1" of tetra really the same as 1" of Silver dollar?

doh! and I thought fish keeping was easy

 

[William]

The once inch rule is a pretty rough guide for fish, and I do believe someone said that you don't have to include the tail in the measurements?

Sounds a bit fishy to me but its a good rough guide I guess, what does a test for nitrAtes in your tank come up as Andi ?

 

[Andi]

Have done 3 readings so far in new tank ....

9/10 : 13/10 : 16/10

Nitrite 1.0 : 1.5 : 1.0
Nitrate 75:75 : 100
Ammoniia < 0.1 : 0.1 :<0.1
PH (broad) 9 : 8.5 : 8.00

can't remember last time I did readings for the hex

 

[tyvex]

hey andi,
i find the safest way of measuring is this,
i have always gone on the basis that it is not volume as much as surface area that restricts the inch of fish.
the best (for stock levels) tanks are wider than deeper ie 20inch high by 24inch wide, although really height is irrelevant within reason.
take a tank 36x15x12 this gives u a surface area of 540 sqr inch, divide this by 12 and you get the inch of fish for that tank = 45 (do not include the tail.)
you could reduce it a bit as a safety measure, but thats about it.
your lucky i have to atleast half that amount for marines
mindya i have a 550ltr tank 5 x 2 x 2 so i can still fit alot in there
ty
ps good luck getting the surface area for a hex

 

[Andi]

thanks ty, guess I'll guess at the hex oh, and my new tanks a bow lol , whish I'd been more interested in maths at school

 

[StiX]

I've always worked it out by 10 sq inch of surface area per 1 inch of fish!

 

[tyvex]

hey sbrk,
yeah, all are a guide, roundabouts only, i err on the side of caution tho.
its amazing how many different ideas out there
i sometimes get fed up with it all, specially the salty side, every one tells you diff things,
sometimes your better just goin with your own instincs,
kinda suck it and see
stay fluffy
ty

 

[Great Lakes]

Both are a good rule of thumb to get a general idea of how much livestock you can have. I also believe that modern filtration lets you get away with a little more. Frequent water changes also aid in this.

Andi, your hex is probably the most inefficient shape tank for oxygen exchange.

Most experienced keepers would opt to go for the suface area rule. Here is a good example of where this can lead.

48"x 18"x 20" high = 75gal, 48"x 18"x 24" high = 90gal, 48"x 18"x 30" high = 135gal. The surface area rule shows that the stocking level would be the same,(48x18=864. Divide by 10 = 86 inches of fish), for all tanks.
86 inches would seem a little extreme for a 75gal, just right for a 90gal, and real sparse for a 135gal. But the oxygen exchange levels would remain the same on all three tanks due to surface area, giving support to the theory that this would be the best way to calculate stocking levels.

I beieve this is why they name tanks the way they due. Historically, shallow long tanks have been called "breeder" tanks. You can have a higher level of fish in them per gallon of water to meet the needs of raising many fry at once. Inversely, a "show" tank is typically very deep, leading to reduced stocking levels, but wonderful for showing off a small selection of fish you are proud of.

Good tank husbandry can make dramatic changes in stocking levels. But experienced fish keepers need some kind of "foul line" to slow down the sometimes unabated enthusiasm of thier apprentices.. B)

 

[Andi]

txs gl, will try not to be too enthusiastic an apprentice

 

[Great Lakes]

lol, I am pretty much one of the overenthusiastic apprentices myself...

 

[StiX]

Nicely explained GL