heard something interesting today...

[Gordinho80]

I was told by an avid aquarium hobbyist that the main factor in stocking an aquarium is foot print, or surface area...

i dont know if this is true or not, he basically said, u can have two tanks, one taller than the other, talking a difference of 90 gal - 150 gal...as long as both tanks have the same footprint/surface area, you can keep the same amount of fish in the 90 as you can in the 150???

can someone please clear this up?

thanks...
Mario

[SpaceButler]

Man, if that's true I never knew it was that drastic.

I suppose if oxygen was your only concern that'd make sense (To me. I'm a novice).

[czcz]

(Newbie speaking)

As I understand, the idea is water surface area determines gas exchange, so to some that is more important than total volume. Some also follow stocking guidelines of 1" of fish/12 sq " of surface area. With variables of surface agitation, fish (I've read Angels prefer taller tanks, for example), etc, it seems best to pick and choose which rules of thumb best fit your needs. I dont think 60gal of stability should be dismissed so easily.

[jgc8fan]

Yes it's true... The surface area is what determines how much oxygen the water can absorb. You need a certain amount of surface area per fish depending on fish size.... But.... Adding aeration (bubble wall, air stone, etc..) is supposed to effectively double the amount of fish that can be stocked for the amount of surface area.

The depth of the tank has little to do with fish capacity. The overall water capacity of the tank does affect the tank's buffering capability, and is supposed to mean larger tanks are easier to maintain (but I've actually had the opposite in my experience).

I disagree with that. Oxygen in the water is not the limiting factor on the capacity of a fish tank, with proper filtration/aeration it should not even be a factor. Amount of waste and more importantly the amount of water for the fish to live in are the important factors. However, the fish would need to have adequate room to move around in, so in an extreme case where the footprint was really small but the tank was really tall that would be a factor. But we would be talking about one poorly designed tank.

[jgc8fan]

Actually... Oxygen in the water is the only limiting factor on the capacity of a tank. the amount of waste effects the ammonia and nitrite in the water. The bio filter will adjust over time to handle the toxins created by the fish. The amount of oxygen in the water is what is always limited. Fish breath oxygen just like every other creature on earth and with poor oxygen the fish will do poorly or die. Aeration will increase the oxygen, but in my experience it's still best to follow some guidelines relating to surface area.

As far as poorly designed tanks... Most of the novelty tanks stores sell (including hex tanks) are poorly designed in relation to oxygen/water exchange.

You will find this info in almost every aquarium book. That's the main reason they always suggest getting the biggest tank you can afford at first... Most newbies get carried away, and tend to overstock the tank until they learn the limitations (at the expense of many fish lives).

[Hooie]

Originally Posted by Gordinho80

...as long as both tanks have the same footprint/surface area, you can keep the same amount of fish in the 90 as you can in the 150???

What he meant was that the 150 can only hold as much as the 90.

YMMV

[RoK]

Originally Posted by jgc8fan

Actually... Oxygen in the water is the only limiting factor on the capacity of a tank.

So with labrynth fish, since they breathe from the air, you can have large amount of them in a tank?

[fisch]

If oxygen is the only limiting factor you could just inject more into the tank similar to how co2 is injected into planted tanks. But i think most people would agree that this is not a good idea. So while oxygen is a factor, there are other things to consider as well.

[sagar77]

Guys,

Yes, this is a topic od debate. It is true that the footprint matters but one should not take this to extremes. I am an avid aquarist and use a more accurate formula (empirical) to stock the fish. It does take into account the footprint but does not over-do it. Here is the formula..... (drum-rolls!)....

Inches of fish= ((length of tank * breadth of tank)/6)* Multiplication factor

The multiplication factor is genrally 0.5. This can be sometimes increased to 0.75 by better aeration, experience and frequent water cahnges. however, it is not generally recommended to go over 0.65.

Hope this helps!

Sagar

[Big C]

Hurray!!! I can go buy more fish!!!!!!!!!

[fisch]

Originally Posted by sagar77

Inches of fish= ((length of tank * breadth of tank)/6)* Multiplication factor

I think this simplifies it too much still and has some flaws. You have to take into account the mass of the fish. For example, while you may be able to house 8-10 1inch fish in a 10 gallon aquarium you can certainly not house 1 8-10inch fish. I think its safe to say that there are no exact formulas to apply to all fish.

[Mazdaman]

I agree with fisch. There is no SET RULE for how many fish in a certain tank.
Tank volume, length, depth, height, the fish in the tank, the filtration, the maintenance, oxygen levels, etc, etc. It is basically knowing your tank and knowing the fish and what there needs are. Most of us know that a 10" oscar CAN NOT go in a 10 gallon tank. it just takes some research and a forum like this where people can come to get the right info for the desired set-up.
If everyone followed the 1" per gallon rule than alot of tanks out there would be way overstocked. (others would be understocked too i suppose)

[TomK2]

A wet/dry trickle filter could probably overcome any surface area deficiency you had, if you were worried about oxygen.

actually i think that it is kinda true

cause the 20 gal long tank has the exact same surface area of a 29 gallon tank just shorter my tank is 18x12x32 and its great i just am still getting used to taking care of fish, im not a newb like most of ya'll(not trying to be offensive) but i know stuff about fish, just done have the money

[Gordinho80]

i think the reasoning behind the statement i heard was this...the person had also said that a 150 gal long could hold more fish as opposed to a 150 gal tall because of the larger surface area...that was my initial point to the thread...it just struck me as odd

[Mazdaman]

that makes some sense to me, but again it depends on which fish.
the long tank could hold more guppiesthan the tall because they are all top-dwellers.

[fisch]

It makes sense because most fish will utilize the extra length and width of the aquarium. for example, bottom dwelling fish dont really need the extra height in the aquarium because they stay towards the bottom so the extra space is wasted on them.