my 160l/40gal tank

Is this tank overstocked? There are many baby Goldish and a couple of adults (some not visible in the dark area). According to some people it should be OK, others say that goldfish need 40gal (80l) per fancy goldfish, so I used to keep two fancy Goldfish and 2 Pangasius fish, but my dad buys me a lot of goldfish.

And many people said that the growth will be stunted, but the local fish store said that it is okay and they also kept a lot of goldfish in a small aquarium for sale. Not to mention my local fish store kept an adult Flowerhorn on a 2.5 gal tank without a lid, and it's not even for sale.

edit: there are 9 baby goldfish, 7 adult goldfish,2 pangasius , and 2 common pleco, the first day i got the baby goldfish 3 got sucked into the filter, after that i cover the intake with sponge

  • 2
    how many litres are your tank and how many goldfish do you have,let me put it this way if you have ten goldfish and the tank is less than 800litres you have too many fish or a too small tank. May 20, 2018 at 5:23
  • 1
    1l = 4.5gal, right? The opinion of the seller is obviously biased because of their incentive to sell and their caretaking because of their incentive to keep the running costs low. If your father continues to buy more fish ask him to stop. May 22, 2018 at 0:14

1 Answer 1


Probably overstocked.

This article keeps to 1 inch of fish per gallon. That sounds about the advice I tend to hear while I live (1cm of fish per litre).

But as the article says, there a many a thing that could change that number.

For more fish per aquarium:

  • plants
  • good filtration
  • Good water replenishment

For less fish per aquarium:

  • The opposite of the above.

For a more precise way of knowing if your aquarium is overstocked, please visit this site and fill in the numbers. That will give you a better answer then we can.

  • I agree on probably overstocked, they also seem to lack basic needs like plants and filtration, which can really add to overall health in the tank. With the amount of babies however I really think OP would do good in downsizing the population. Perhaps the dad would like a tank of his own?
    – Summer
    May 22, 2018 at 11:58
  • 1
    here is a calculator to find how many goldfish you can have in a tank thegoldfishtank.com/tank-size-calculator May 22, 2018 at 12:24
  • the site says 3 fancy goldfish ;-;
    – tristan
    May 26, 2018 at 13:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.