Monster Cichlids: Fish to Tank Ratio

[TheViciousBitch]

Hello experienced Monster Central/South American keepers!

I am planning a future tank. I would love to get a realistic understanding of how many 12-16 inch American Cichlids can be housed in 300 gal tank? 600 gal tank? 1000 gal?

Is there a rule of thumb from your personal experience? Does the number of fish/fish inches follow a linear or exponential scale as the tank size increases.

My concern is not water quality, my concern is enough space for the fish to be happy.

Assume that 1) The tank would be massively over filtered by 3x-4x, 2) handled by an experienced fish keeper with weekly deep cleaning at a minimum, 3) the tank is only large cichlids - a Flowerhorn, Viejas, Oscar, Jaguar, Texas, Green or Red Terror, etc. (Please remain calm - I would be cutting/adding to that list base on suitably… just trying to give you a clear idea I do NOT mean sevrums or anything <12”).

Does having multiple or only one of a type impact their behavior or need for space?

Thanks for your help!

 

[esoxlucius]

My concern is not water quality, my concern is enough space for the fish to be happy.

With a tank full of monster cichlids i'd have thought water quality would be a primary concern.

Given the nature of big boisterous cichlids, and the fact you seem to want to keep lots of them, and keep them "happy" too, then I think you are looking at a huge aquarium in order to give them all their "territories", otherwise the bickering and in house fighting associated with these fish will be rife.

 

[GolemGolem]

Dunno, always seems like a gamble to me. If I had the resources to go for it I'd want as big as I could go with a spare 125 or two on hand and ready for anyfish who is too big an butthole or wuss as the situation evolves. Need a new spare tank myself in the next couple months before my kribs and/or sunfish start getting ready to breed again.

 

[duanes]

A random rule of thumb ratio I use, is each adult cichlid needs 10 gallons of water volume per inch.
This is "not" using only its length, but adding together L + W + H.
So as an example ....
a single 14" inch Vieja, that is 10" tall, and almost 4" wide needs minimum of about 240 gallons.
add a 15"L managuense that is 6" tall and 4" wide, the tank needs another 250 gallons.

Of course none of these calculation take in the instinctual territoriality that either cichlid might display as maturity sets in in a mixed community, and all Central American cichlids display different degrees of territoriality (aggressiveness or going wacko over night (as is often posted here), is sometimes used erroneously substituted for territoriality when it sets in) at different stages of life .

And as exolucius mentioned, water quality would be a major player in the scenario.
Although filtration plays a somewhat partial roll, most filtration doesn't take care of nitrate (water changes are practically the only solution).
I consider the efficacy of most commercial filters to be vastly over rated.
And consider nitrate as simply an indicator of other deleterious substances in the water.
Nitrate is not just the bad single entity, but we don't have the ability to test for all the others.
So for whatever amount and size of large cichlids kept, in whatever volume of water, its the management of nitrate and its nasty allies that controls the population density.
I like to keep nitrate on or below 5ppm, to avoid HITH disease, and the other health issues, we see mysteriously pop up in the disease section.

 

[tlindsey]

I would love to get a realistic understanding of how many 12-16 inch American Cichlids can be housed in 300 gal tank? 600 gal tank? 1000 gal?

Welcome aboard
Definitely depends on the species.
There are cichlid species that one or a pair that will claim a 300 or 600 gallon easily.
Also agree with esoxlucius about water quality.

 

[Gajzila]

A random rule of thumb ratio I use, is each adult cichlid needs 10 gallons of water volume per inch.
This is "not" using only its length, but adding together L + W + H.
So as an example ....
a single 14" inch Vieja, that is 10" tall, and almost 4" wide needs minimum of about 240 gallons.
add a 15"L managuense that is 6" tall and 4" wide, the tank needs another 250 gallons.

Of course none of these calculation take in the instinctual territoriality that either cichlid might display as maturity sets in in a mixed community, and all Central American cichlids display different degrees of territoriality (aggressiveness or going wacko over night (as is often posted here), is sometimes used erroneously substituted for territoriality when it sets in) at different stages of life .

And as exolucius mentioned, water quality would be a major player in the scenario.
Although filtration plays a somewhat partial roll, most filtration doesn't take care of nitrate (water changes are practically the only solution).
I consider the efficacy of most commercial filters to be vastly over rated.
And consider nitrate as simply an indicator of other deleterious substances in the water.
Nitrate is not just the bad single entity, but we don't have the ability to test for all the others.
So for whatever amount and size of large cichlids kept, in whatever volume of water, its the management of nitrate and its nasty allies that controls the population density.
I like to keep nitrate on or below 5ppm, to avoid HITH disease, and the other health issues, we see mysteriously pop up in the disease section.

For ONE Vieja need 240 GALLON TANK????? FOR ONE (1)? BROUUUU... Where do you live....

 

[Gajzila]

My house is 60 square meters, so for 2 Vieja's I would have to evict my wife and children from the apartment in order to adopt them. hahahahahaha... You are KING!

 

[Midwater]

It is not just the size of your tank, it is the size of your filter. A 300 gallon (what ever that is in litres) with a tiny filter will not support the same load as a 300 gallon with a 250 sump.

 

[jjohnwm]

As usual, a lot of the replies seem to come from people who don't keep fish alive long enough to understand how big they are as adults. Just as an example, a 14-inch Vieja represents probably 6x - 8x the biomass of a six-incher...and it gets to that size within a couple or three years.

So...is it possible to keep some of these monsters "for life" in aquariums that are, by any reasonable standard, too small? Of course it is. After all, "for life" can be re-worded as "until it dies"...even if that happens long before it should or would have if proper conditions had been provided.

 

[Gajzila]

As usual, a lot of the replies seem to come from people who don't keep fish alive long enough to understand how big they are as adults. Just as an example, a 14-inch Vieja represents probably 6x - 8x the biomass of a six-incher...and it gets to that size within a couple or three years.

So...is it possible to keep some of these monsters "for life" in aquariums that are, by any reasonable standard, too small? Of course it is. After all, "for life" can be re-worded as "until it dies"...even if that happens long before it should or would have if proper conditions had been provided.

And ONE Vieja need 240 gallons?