why cant this fit?

[maxima423]

so i was in a LFS today and i saw a Tropical Fish for Freshwater Aquariums: Cuvier Bichir , the guy next to me asks me if this fish can fit in a 20g LONG tank, so i said i dont know, so he called over a employee and asked the same question and the employee said "no" as well, so the guy was wondering why cant a 1ft long fish fit in a 30inch long tank? can anyone answer? the dude kept saying, the tank is more than twice the body length yada yada yada, hes right but whats the rule with the length of the fish and length of the tank?

 

[Crepe]

For sedentary fish you are going to to need a tank twice as wide as the fish is long. For mobile fish larger than 1 foot make that 3-4 times larger. That's the rule I go by.

 

[maxima423]

mhmmm i see, so what if its less than 1foot? lets say a 6-8inch fish, what would you go by? over 1foot mobile fish makes sense to me, so does the sedentary fish

 

[Crepe]

Depends on what type of fish you're talking about. I would stick with the 3x rule for 6-8 inch fish.

 

[maxima423]

ah ok, got it, seems to make sense

 

[Crepe]

After all, most 75g cichlid tanks are going to hold 6" fish and are 48 x 18 x 20 inches.

 

[maxima423]

yea, i already have a 55g 10g and a 20g long tank, i dunno if i want to do a 55g just yet, i am thinking of which one i want to start after i get back from july 4th weekend, so i am just asking these questions and hopefully people would help me =]

 

[taylorodw]

I generally agree with Crepe, with the addendum that the tank should be, at bare minimum, 1.5x as wide as the fish (for sedentary fish), so that it can turn around comfortably. Really though 2x is realistic as a bare minimum for more active fish, 3x is best but sometimes unachievable with the bigger fishies.

 

[maxima423]

yea i was thinking 2x for active fish aswell, its good to know cause i am making a community tank and i can figure out what i want to put in

 

[mgamer20o0]

20 L 30 x 12 x 12
Polypterus senegalus senegalus, Gray bichir : fisheries

they get larger than 1 foot. fishbase has it as 19 inch. even if the 1 foot is correct.... there is a lot more in stocking then these stupid rules like inch per gallon or tank twice as long as the fish.... creepe is right on where stating the room it needs to turn around takes into account. so does mass and bio load. at least the lfs said no.

 

[FishEggs]

i have a nine inch senegalus in a 75 gallon and i wouldn't put it in anything smaller. my bed room is twice as wide as i am tall but i wouldnt want to live in just my bedroom the rest of my life.