tank depth front to back ratio to fish size opinions

[henward]

just wondering, for the MFKs out here, what sort of ratio do you personally abide by when keeping monster fish.

example, say the tank depth front to back is 50 cms, what maximum length fish would you put in a 50 cm tank?

see, i have seen people say, you can put a fish, and the depth should be 10 - 20% more than its length, some say should be more.

[A.PROPHECY]

depends on what kind of fish

[henward]

ok, lets say a...... giant gourami

i mean just as a general opinion i guess

[David R]

depends on what kind of fish

Fully, something flexible like an arowana, or something inactive like a bichir would generally be alright in any tank thats wide enough for them to turn around in.

For the GG, just have a look at Helens tank at HFF, its not really that wide, just wide enough to turn around in. Wider would be better tho, they're not really flexible...

[Ianab]

I also think it depends on the species of fish, and also the other tank dimensions. If the tank is 8ft long, then it doens't have to be as wide, there is swimming space, do a 3 point turn, swim back. Thats the theory I'm using with my 'new' 1.8m tanks and my plecos anyway.

A gourami naturally comes from fairly cramped conditions I believe, Paddy fields and small streams. They aren't really an open water fish, so they can handle smaller dimensions, as long as your total tank volume is big enough.

Something faster swimming like a bala shark on the other hand I would suggest you want twice the fishes length for it to turn around easlily, so a 30cm bala should probably have 60cm depth and probably height as well.

Depth is also debatable. Many fish could live quite well in water not much deeper than their body, gourami and plecos for instance. The eels in by back garden seem quite happy in 10-15cm of water, and they are 50-100cm long. When they swim up the rapids they are actually 1/2 out of the water.

But generally larger tanks are usually at least 40-50cm deep, plenty of depth for most fish.

Ian

[Anna_&_Chris]

For the GG, just have a look at Helens tank at HFF, its not really that wide, just wide enough to turn around in. Wider would be better tho, they're not really flexible...

Chris sez she gets uglier everytime we go to HFF :lol:

[David R]

She aint pretty! I often wonder if the name had anything to do with the fact that Rolf Jansens wife is called Helen.... :lol:

Ian is right on the money, look at the habitat of the fish. Tinfoil barbs and bala sharks are going to need plenty of swimming space, big lazy pleco's don't need so much. I've seen video's of 5' Arapimas being kept in shallow pools, some would say its cruel, but check out this video of them in habitat:

[Ianab]

Imagine trying to catch one of those to move it to a new tank???

If it takes a jaguar to drag one down

Ian

[David R]

Hah, talk about coincidence, I just finished reading this thread on MFK: How We Moved Our 5 Foot Arapima

Certainly not impossible with the right equipment and planning.