Goldfish dosent grow

[Savethemall]

Hi, I have a 450L tank with 13 small to medium goldfish{ the biggest is 15 cm}. there are 2 external filters doing around 3200 L/H. Water P are 0,0,20 and were doing wc of 30% once a week. im feeding with JBL Novo Pearl.
all of the goldfish are rescued and some of them i have for around 3 years. it seems like when i bring a small new guy he often grows but then stops in a relative smal size. the 15 cm one i have for 3 years and he hasnt grow in the last 2 year..
what do you think is the reason? is it possible its some kind of health issue?

 

[MatteoTheEnder22]

Maybe its stunted growth. when I had goldfish they didn’t stop growing but it may be genetic and also how often are you doing water changes especially with so many goldfish and more importantly what temperature is the water?

 

[Savethemall]

once a week 30%/ temp is pretty high beacuse its summer, 29C

 

[duanes]

What is your nitrate level in ppm.
With only a 30% water change once per week, I would imagine its what I consider high, and I believe any high nitrate level (and some other compounds the water changes dilute) can stunt growth.
I bought these goldfish at an aquarium club auction, they were maybe 2" - 3"at the time.(5cm-7c,m)

In about a year they were this size


I do about 30% water changes on my tanks every other day, and try to hold nitrate below 10ppm.

 

[jjohnwm]

I've had a few of what might be referred to as "rescue" fish over the years, some of which had survived truly abominable conditions for extended periods. I'm talking about water conditions so bad that I took several days to slowly acclimate them, for fear that the sudden transition to decent water might have shocked them to death.

The seat-of-the-pants impression I got from keeping some of these fish for long periods after receiving them is that they would never attain the full size potential that one might expect from the species. Fish that would normally attain a length of 10-12 inches would slow or almost stop growing at barely half that size if they spent their early days in poor water, or with poor nutrition.

Just a thought, and with no research or experimentation to prove or disprove it. Depending on the source of your fish, this might be a partial explanation?

 

[esoxlucius]

I agree with jjohnwm . Arguably goldfish have long been one of the most abused fish in the hobby. The fact that they're rescued fish means you can't really know the state of the conditions they once lived in. If they were exposed to very high and prolonged levels of nitrate as young fish then that would more than likely scupper any future growth.

duanes got his fish very small, he's totally anal about his water, and look at the results. The pictures showing the size and health of those fish speak volumes.

All you can do now is to give your rescue fish the best possible chance of a better life than they once had. Keep your water good, number one rule of the hobby, the rest looks after itself.

 

[Savethemall]

nitrate is 20 ppm at tops, like right before the weekly WC. I know its not the best but i dont htink its bad enough to creat stunt growth. Most of the came for very bd places , but there are some that ive rescued just a day or two after theyv been bought, so i would expect them not to suffer to much of long term demages..

 

[jjohnwm]

Depends upon where they were bought; goldfish and feeders, along with many other fish, could be spending weeks or months in abysmal conditions before they are ever purchased. It's not only unthinking purchasers who neglect or mistreat fish. Sometimes it's done professionally.

Stunted fish don't necessarily look or behave unhealthy per se, even if their growth slows or stops before it normally would. I've read several debates online in which it was argued that stunting was not undesirable since it kept fish at a more manageable size. I personally find that idea ridiculous; I think that fish should be chosen only if they naturally achieve a size that is able to live comfortably in a tank, rather than "force-stunting" unsuitable fish so that they can be shoe-horned into substandard housing. Sadly, MFK is rife with this kind of thing, even if it is unplanned; for every Monster Fish that goes into a large-enough tank, there seem to be dozens who don't...but still come home anyway. A Redtail Cat sitting in a 50 or 100 gallon "grow-out" tank isn't acceptable, even if the owner professes to some vague plan to get a larger, more suitable tank "soon". IMHO permanent housing should be available, or at least in progress, before monsters are purchased; many of them grow way too fast to wait for "someday".

I applaud the idea of a "rescue" as long as it really is one, i.e. the fish is truly going from bad conditions to better ones. Too many so-called rescues are really just a transfer from one torture chamber to another. I'm not painting you with that brush, S Savethemall , but you might want to consider curtailing future additions to your tank. Thirteen goldfish in a 450liter tank is definitely getting a bit crowded, especially if even some of them continue to grow. You don't want to find yourself becoming the guy from whom someone else starts rescuing fish!

Just something to consider. Good luck!

 

[Savethemall]

Depends upon where they were bought; goldfish and feeders, along with many other fish, could be spending weeks or months in abysmal conditions before they are ever purchased. It's not only unthinking purchasers who neglect or mistreat fish. Sometimes it's done professionally.

Stunted fish don't necessarily look or behave unhealthy per se, even if their growth slows or stops before it normally would. I've read several debates online in which it was argued that stunting was not undesirable since it kept fish at a more manageable size. I personally find that idea ridiculous; I think that fish should be chosen only if they naturally achieve a size that is able to live comfortably in a tank, rather than "force-stunting" unsuitable fish so that they can be shoe-horned into substandard housing. Sadly, MFK is rife with this kind of thing, even if it is unplanned; for every Monster Fish that goes into a large-enough tank, there seem to be dozens who don't...but still come home anyway. A Redtail Cat sitting in a 50 or 100 gallon "grow-out" tank isn't acceptable, even if the owner professes to some vague plan to get a larger, more suitable tank "soon". IMHO permanent housing should be available, or at least in progress, before monsters are purchased; many of them grow way too fast to wait for "someday".

I applaud the idea of a "rescue" as long as it really is one, i.e. the fish is truly going from bad conditions to better ones. Too many so-called rescues are really just a transfer from one torture chamber to another. I'm not painting you with that brush, S Savethemall , but you might want to consider curtailing future additions to your tank. Thirteen goldfish in a 450liter tank is definitely getting a bit crowded, especially if even some of them continue to grow. You don't want to find yourself becoming the guy from whom someone else starts rescuing fish!

Just something to consider. Good luck!

Of course i thinm about it. when thye grow i take them to a pond.