THE BIG QUESTION: WHAT DETERMINES THE MINIMUM TANK SIZE???

[Maccoy]

This is because you lack experience in the matter. Once, or if your aro gets to 30"plus your opinion will change. Actually you could see how wrong you are right now. You think it to be OK to keep a 8" silver aro in 20" long 10" wide 10 gallon tank? Or how about a 10"er in a 24x12" twenty gallon?

Obv there is min ammount of space req for every fish

 

[Sab_Fan]

I agree, any theory about minimum sizes has be subjective to the type(s) of fish being kept . . . common sense also has to play a role; do your research on the fish you're interested in, and then use your best judgement

preferably err on the side of larger vs smaller . . .

 

[Bderick67]

Obv there is min ammount of space req for every fish

So then why the bigger the fish the smaller the tank size by ratio?

 

[TinyD]

How fat is your pocket book!

 

[scottswald]

for long skinny fish, length is the factor

for fatter fish, bioload also comes into play

 

[Darth Scohin]

I Like to say length of the tank to be at least 3-4 times the length of the fish and the width to be 1.5 times the length of the fish for more active fish 2-3 times wider....And for depth that just depends Example:

30" Silver Aro Tank would be (LxWxH)120"x45"x45" this is quite a big tank but the aro would be comfy....however, for less active fish Polys

12" Senegal 48"x18"x18" a 75gal or even a little tetra

4" Congo Tetra 16"x12"x12" now obviously I've realized this really only works for big fish so....

700th POST

 

[MonsterMinis]

I think it was best put.. the fish tell you.. if you're willing to pay attention. for me.. it depends on the mass of the fish.. it's general natural tendancies.. are they a lazy lay about, active constantly, or "spastic", or "bullet proof" .. IE is the fish going to not do harm to itself in it's day in day out life in the tank? Is it showing signs of life? I try and breed everything.. silly as it sounds.. happy animals breed a majority of the time, unhappy ones will not. If my fish are pairing off, showing breeding signs, or otherwise exhibiting nesting behavior ect... and are thriving in general. I am happy with their tanks. as a general rule I follow length of fish min width of tank 2x fish length to length of tank... but thats a bare min, and for fish that are calm and not prone to spooking. and tbh a general idea of the tank size I'm going to double.. Bigger is always better, and if my tank isn't over-filtered.. it's not properly filtered imo.

 

[vfc]

I Like to say length of the tank to be at least 3-4 times the length of the fish and the width to be 1.5 times the length of the fish for more active fish 2-3 times wider....And for depth that just depends Example:.......

4" Congo Tetra 16"x12"x12" now obviously I've realized this really only works for big fish so....

With that standard, I could keep a school of neons in a tea cup..lol.

As was posted before, we are all guilty of under sizing tanks for large fish. We should apply the same standard we use for small fish; say 24:1 for the length, for large fish. So a 12" P-bass would need a 24' long tank.

 

[Zander_The_RBP]

IMO the foot print is the major factor in determining what fish you can keep. 3-4 x the length of the fish (depending on activity level) and 1.5-2 x the width (again depending on activity level) are usualy what i consider to be the minimum (for large fish) for small ones like tetras i just use the 1 cubic inch of fish per gallon.

volume to me plays a roll in HOW MANY fish(to dilute wastes) of a particular species you can keep but foot print determines WHAT fish you can keep

mind you if you have a large foot print you can offset having a slightly smaller volume by over-filtration (again to a certain degree)

 

[SimonL]

So then why the bigger the fish the smaller the tank size by ratio?

This is the paradox present in all these "minimum tank size" threads, the answer of course is practicality. That is the reason why a "min. size tank" for a Tiger barb is 20 gallons, and a Tinfoil barb a 180.

These fish have the exact same body shape and swimming habits, yet a 2" Tiger barb has 12x it's body in length, 6x in width and 8x in height. If you apply those same dimensions to a foot long Tinfoil barb, the minimum size tank would be 12 feet long, 6 feet wide and 8 feet high, or roughly 4300 gallons.

Reversing that logic and using the minimum tanksize/body ratio of the Tinfoil and applying it to the Tiger, you end up with a minimum size tank, for a 2" Tiger barb, being 12" long, 4" wide and 4" high or a whopping .67 gallons.

Appropriate tank size has very little to do with the fish and everything to do with the norms of fishkeeping, which are determined by practicality.