Inch Per Gallon

[cbwmn]

I think for a beginner, 1 inch per gallon is a good rule to live by. This rule can be stretched if you add live plants to the tank, increase the frequency of water changes, upgrade to awesome filtration (canister instead of hob).
Personally, in my 10G tank I've got about 22 inches of fish (guppies, mollies, platys), but I've also got about 2 pounds of anacharis, java moss and christmas moss in the tank as well. Nitrates are ~4ppm, nitrites and ammonia are 0ppm. I also do about 30% water change about once a week.

If you put a 5 inch Discus in a 10 gallon tank, it would not live long.
You also have to consider body mass.

Charles

 

[bs6749]

If you put a 5 inch Discus in a 10 gallon tank, it would not live long.
You also have to consider body mass.

Charles

I'm not so sure about that. A friend of Jack Wattley actually bred discus in 10g tanks. There is an article out there somewhere and I need to find it!

 

[cbwmn]

I'm not so sure about that. A friend of Jack Wattley actually bred discus in 10g tanks. There is an article out there somewhere and I need to find it!

It may live, but not happily.
Would you like to live like like Scott Peterson?
He lives in a 4 ft X 9 ft cell for 19 hours a day.
A 5" discus can swim four times it’s length horizontally
and two times it’s length laterally
and twice it’s height vertically in a ten gallon aquarium.
That's just plain cruelty.
I still stand by my statement; you HAVE to consider body mass
when figuring how many fish an aquarium can support.
You can probably support 20 white clouds in a 10 gallon with enough filtration,
but not ONE discus or other large fish.

Charles

 

[bs6749]

Not living happily? Then how do you explain them reproducing? If a fish is stressed, the LAST thing it will do is reproduce. Now take into consideration that you have two 5" fish in a 10g tank lreproducing and you should be able to see that neither one is stressed.

I agree, it's not realistic to keep them there, but who is to determine exactly how large the tank SHOULD be for them? How do we know that even if we had a 1000g tank with a pair of discus they wouldn't feel confined? We really don't (as far as I know) so we have to look at their behavior. Color change and "personality" changes in fish are indicators that something is wrong and we need to pay attention to them to figure out what the problem is.

I think it all boils down to an ethical dilemma and people trying to put themselves in the position of the fish.

 

[krap101]

Suprisingly no one has voted for it. The inch per gallon is something used as training wheels for people who are just starting. If its well filtered, and there's enough plants, I'm sure you could maybe quadruple (or even more) the inch per gallon *theory*. But then again, you need to look at aggressiveness, movement, size, bioload, and location (top middle bottom)

 

[krap101]

It may live, but not happily.
Would you like to live like like Scott Peterson?
He lives in a 4 ft X 9 ft cell for 19 hours a day.
A 5" discus can swim four times it’s length horizontally
and two times it’s length laterally
and twice it’s height vertically in a ten gallon aquarium.
That's just plain cruelty.
I still stand by my statement; you HAVE to consider body mass
when figuring how many fish an aquarium can support.
You can probably support 20 white clouds in a 10 gallon with enough filtration,
but not ONE discus or other large fish.

Charles

You also have to look at the fact its being bred, and I'm sure once the babies are born, they will get moved into a bigger tank. It is much easier to watch/manage a fish in a smaller tank. When your having a baby, do you do it in a 10 x 10 hospital room or a 20 mi x 20 mi open mountain range? (maybe its a bad analogy but it gets the job done)

 

[Brad.Sedore]

you guys want to talk about over stocking hows this for you.

one time we had to keep a 3 ft caimen croc in a 40 gallon tank for 2 weeks while we awaited his new enclosers arrival... how does 100% water changes every day sound to you guys?


-Brad

 

[colematthewmalaka]

With small fish i find it works well but many people on this forum think its a load of crap i don't believe that and think that it should be used sensibly.

 

[bs6749]

how does 100% water changes every day sound to you guys?


-Brad

Not nearly as bad as the guys that keep discus and change out 50% every day on dozens of tanks, which can amount to hundreds of gallons per day. Some breeders in Asia do 100% water changes 6 or more times per day.

 

[Leeny]

I don't think it's a good rule to live by because you also need to account for the width of the fish. Fish aren't 2D creatures, they have mass which means waste. The rounder the fish, the more waste produced.

 

[cfd]

Basically, it's a good guideline for smaller fish but it's silly when people follow it as if it's some kind of law.

For example, I used to have 4 mollies (about 3" each) in a 10 gallon and they were just fine.

 

[cbwmn]

I don't think it's a good rule to live by because you also need to account for the width of the fish. Fish aren't 2D creatures, they have mass which means waste. The rounder the fish, the more waste produced.

Thanks Leeny
That's what I mean. Body mass should be the primary consideration, not the length of the fish.
Charles

 

[boogie]

So everyone - body mass - so does that mean if I have skinny long fish I can keep a lot more fish? I seem to get a lot of crap from all sorts of people on this forum and others when I mention what I have in my tank - yet my fish are healthy. I'm always amazed when people are extremely rude because of difference of opinions. I even stopped coming to this site for awhile because people need to push their opinions to the point of obnoxiousness. So, without being obnoxious, what about eels and gobies and knife fish that are long and lean? What do you think about that, especially since I have 6 filters (no one has that many that I have ever seen), water changes 30% weekly, 1/2 planted 125 gallon aquarium. According to this site on another thread and another fish forum, I really couldn't have much at all. Just wondering since this thread seems a little more liberal in allowing people to keep more than a couple fish in a tank, even in a 125. But, I'm sure I'd still be looked at as a fish Hitler anyway.

 

[cogburn]

well... boogie... what do you have in your tank?

 

[boogie]

Eels, gobies, knifefish

 

[Fishyfanatic]

This is why the inch per gal guideline isn't followed all the time. It depends on the type of fish in question. Some fish, like Bala's, require larger tanks due to their adult size and aggression. Same with African Cichlids. You could theoretically keep a 5" African cichlid in a 5 gal tank going by the inch per gal guideline. But in all reality? No way. It's the agression factor and the need to have plenty of free space to swim. Some fish need the open space whereas others, like Corys, do not.

 

[SomethingSmellsFishy]

nah, I don't live by that rule. There are so many other factors one must take into consideration when deciding how many fish to keep in a tank. Some fish are messier than others, some have special needs, etc.

 

[Bigfoot1030]

I agree there are too many other factors to consider.

 

[cogburn]

even in the saltwater side of it a little... tangs get to be what 6"... but they need a 6' tank cuz they need swimming room... so by the inch rule i could have a yellow tang in a 12 gallon nano right... WRONG

 

[Bigfoot1030]

Cogburn, great example!! Same can be said with a ten gallon. 10 1" neons or 1 10" Oscar.