Dispelling the inch per gallon rule.

[blackwolfXKAV]

Ok, i know there are definite disagreements on this, and it includes SW.
I'm just trying to dispell the 'myths'.

First off, i was taught that the ipg (inch-per gallon) rule only worked up to fish that were three inches and that when it was adjusted, it would generally work like this:
1 inch per 1 gal
2 inch per 2 gal
3 inch per 3 gal

I was also told that it only worked up to fish that got to 3 three inches only.
It had also been said that it could only be applied to fish that grew to that lenght, not just measuring any give fish in length only. I was told to remember that in general, once a fish got past three inces, it would bulk out, thus creating an uneven measurement.

On a side note, one source for SW stated that it was a 6"pg rule, but i doubt that this by any means an efficient way.

Any thoughts on this?

 

[beblondie]

Its actually a generalized guide thats been mislabeled a ''rule'' after years of common misuage

 

[Rbishop]

What about if one 1" fish doesn't get along with another 1" fish because they do not get along with one another?

What if the fish involved do not have the same dietary needs?

Temperature?

Water chemistry?

Free swimming space?

Male/female issues?

Spawning issues?

Protecting fry?

Growing to adult size?

 

[blkwdw13]

I think rbishop pretty much covered it.

 

[Max]

I agree he sure did! Just as an added example 500 gal tank and 2 different sort of clown fish and you have a war. 1000 gallon tank and 2 different tangs," or anything that looks too much like a tang," and you'll end up with at least one dead fish.

 

[RockabillyChick]

i always thought that most marine tanks were very understocked compared to freshwater tanks?

 

[Rbishop]

RC...hadn't ever thought about that, but now that you mention it, it does seem that way. Okay you SW folk, are we seeing things (or not)?

 

[jm1212]

they are. marine fish need around twice as much space as FW.
but still it would be the same as putting two male convicts in a 100 gallon of so. but still even then you cant put a 24" Emperor Angelfish into a 48 gallon. everything else stays the same but you cut stocking in half
(by the way if you did happen to have a 1000 gallon tank you could have a school of regal tangs [hippo tangs])

 

[SnakeIce]

Just addressing bioload supported by the volume of water one would have to compare volume of fish, yes the actual volume the fish takes up, to volume of water.
This is a simplistic method still since herbivores produce more waste than omnivores and some fish have higher metabolizms than others.


Then there are questions of agression, a more agressive fish will not let as many fish reside with him.


The final point I look at out of the many considerations is what it takes for a fish to thrive. This generally will be much less densly stocked than what the system will support biologicly. Fish need territory and personal space that isn't constantly invaded by other fish. Even schooling fish need space for that school to exsist in peace without other fish invadeing that school.

A further explanation of these basic points is found in the link in my signature.

 

[Max]

Salt water tanks usually have any where from 1/2 to 1/4 of the # of fish than a f.w. tank. In reefs it tends to go to the lower number due to the fact that inverts need really clean water and a lot of them can get pretty big to.
There is a little more to keep in mind with s.w. especially with reefs you pretty much have to make a semi-functioning eco system. Its a whole lot easier for it to more or less manage it's self than for a hobiest to try to do everything by artificial means like you'd do in most f.w. and fish only s.w. tanks.