How to easily calculate fish population...?

[GuppSword]

Hi,

I've been thinking about adding a Goldfish or two to my aquarium but I'm not sure if I'm overpopulating it; I currently have nine swordtails and five guppies together in a 20 gallon tank.

There is a way to calculate this according to the size of the fish ... per gallon of water, etc, but for me it is very cumbersome.

I found this chart on a website, https://www.tankarium.com/aquarium-stocking-calculator/ but it doesn't have the swordtails, at least not by that name (?) plus it doesn't seem to calculate Goldfish for a 20 gallon tank.

Do you know of a more practical way to be able to know at least with some certainty if I could include two Goldfish to my aquarium.

Thanks for any related comments, they always help a lot!.

Regards


*Bottom filter with a Tetra Whisper air pump recommended for up to a 40 gallon tank.

 

[Deleted member 149562]

A single Goldfish needs a minimum of 30 gallons, so sadly your aquarium will not be sufficient for two of them and even if very young they will soon outgrow the aquarium and require either a much larger aquarium or a decent sized pond outside in the garden.

 

[sharkweek178]

This site isn't perfect, but it's a good guide.

https://www.aqadvisor.com/

You don't want to get to 100%. Ideally, 75% or less. Maybe some of the more experienced members could weigh in.

 

[Slaphppy7]

This site isn't perfect, but it's a good guide.

https://www.aqadvisor.com/

You don't want to get to 100%. Ideally, 75% or less. Maybe some of the more experienced members could weigh in.

AqAdvisor suggests that ALL of my tanks are overstocked (>100%), but like you say, it's a guide, not gospel...

 

[GaryE]

In the unlikely event that water quality (goldfish digestive systems aren't unlike what a cow has) didn't kill your swords and guppies, a successfully grown out goldie will eat its soon to appear tiny tankmates.
But an indoors goldfish is only for aquarists who want to work very hard. Water changing? Until you keep a goldie correctly, you don't know the meaning of water changes. Each goldie should have 20 to 30 gallons to itself, with no other fish, good filtration and a hard working owner.

 

[GuppSword]

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@wasmewasntit,

Surely there is no difference in the growth of these fish, whether in ponds or fish tanks? -- I believe their growth in a fish tank should be limited. There are also different types of Goldfish.

I have seen some hobbyists out there with Goldfish living next to guppies and swordtails in tanks even as small as 15 gallons.

*I am just stating my doubts, I am not an expert.

Thanks.

 

[Deleted member 149562]

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@wasmewasntit,

Surely there is no difference in the growth of these fish, whether in ponds or fish tanks? -- I believe their growth in a fish tank should be limited. There are also different types of Goldfish.

I have seen some hobbyists out there with Goldfish living next to guppies and swordtails in tanks even as small as 15 gallons.

*I am just stating my doubts, I am not an expert.

Thanks.

Goldfish along with every fish should never be kept in aquariums that are too small for them. It is not only extremely unhealthy since they are possibly one of the biggest producers of waste in the domesticated fish world, but to purposely stunt the growth of any animal to suit a smaller living accommodation is exceptionally cruel treatment, a Goldfish of any variety can and will grow very large. The 30 gallon per fish minimum is for a juvenile, as they grow, they require larger aquariums to the stage where aquarium life is no longer safe for them and a pond is essential.

Goldfish do not really belong in an aquarium, they need space to roam in ponds where they can grow to their full size and enjoy life, not crampt into a glass box where they cannot turn around and are swimming in their own waste. Maintaining an aquarium with a Goldfish is difficult due to their need of far greater filtration, higher than normal water changes and so forth. They are simply not suited to aquarium life and especially not with other fish like yours that are livebearers and will be significantly smaller...thus seen as prey.

Totally unfair on the fish and absolutely cruel.

 

[DoubleDutch]

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@wasmewasntit,

Surely there is no difference in the growth of these fish, whether in ponds or fish tanks? -- I believe their growth in a fish tank should be limited. There are also different types of Goldfish.

I have seen some hobbyists out there with Goldfish living next to guppies and swordtails in tanks even as small as 15 gallons.

*I am just stating my doubts, I am not an expert.

Thanks.

I have even seen some hobbyist keeping two goldfish in a 1,5G bowl.

 

[sharkweek178]

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@wasmewasntit,

Surely there is no difference in the growth of these fish, whether in ponds or fish tanks? -- I believe their growth in a fish tank should be limited. There are also different types of Goldfish.

I have seen some hobbyists out there with Goldfish living next to guppies and swordtails in tanks even as small as 15 gallons.

*I am just stating my doubts, I am not an expert.

Thanks.

I grew up with the myth that goldfish only grow to the size of their tank. That's only partially true. Their bodies stop growing but their eyes and organs don't stop growing.

 

[Deleted member 149562]

I am detached from any philosophy that considers certain points about what is and what is not animal cruelty.
Don't we eat fish?, don't we keep them in an aquarium for our pleasure?, what is "animal cruelty"?.
I have also seen goldfish in a 1,5G bowl

You simply do not put ANY fish into an aquarium that is too small for them. It is cruel and inhumane.

Granted fish are not cute and cuddly but they are living beings, they deserve upmost respect from their owners and we as fishkeepers have a responsibility to not keep them in a cruel and inhumane environment where they will suffer. It is as simple as that.

 

[GuppSword]

Very compassionate, 'touching', but ... don't you eat fish?.

-- I'll leave it at that, you might want to open a thread on this topic elsewhere.

thanks

 

[Essjay]

On this forum, we believe in the welfare of the fish in our care. When we read of someone keeping fish in inappropriate conditions we tell them. It is then up to that person if they want to act on what they are told, or not.

 

[CaptainBarnicles]

Very compassionate, 'touching', but ... don't you eat fish?.

-- I'll leave it at that, you might want to open a thread on this topic elsewhere.

thanks

Wow...you should not be keeping fish as pets!

Would you keep a dog locked in a tiny cage it's whole life? Would you put a horse in a tiny shed and not let it out? We domesticated animals not only to work for us but to love and admire them. If we decide to keep pets then we have a moral responsibility to be kind, loving, intuitive and give them the best life we possibly can

 

[Glenn407]

I grew up with the myth that goldfish only grow to the size of their tank. That's only partially true. Their bodies stop growing but their eyes and organs don't stop growing.

I've read that's a myth as well. I personally don't know. I'm just reflecting on the thoughts and very extensive article from some guy by the name of David Bogert on a really nice site I ran across called Aquarium Science. For all I know he's some lone wolf but the site is really good. I've no doubt much of what he says about a number of topics contradicts many beliefs.

 

[WhistlingBadger]

Let's keep things on-topic, friends. Fish eating and Indian religious beliefs are quite outside the topic and should not be discussed in this thread.

As for aquarium size, there are many different opinions, and obviously the vast majority of goldfish live in small tanks. There are relatively few absolutes in this hobby, but generally the accepted wisdom on the forum is such for a reason. I always advise beginners to abide by AqAdvisor, as they are very conservative and will keep you from overstocking. Once you have some experience, you can adjust.