I bought today two fish and a small filtered tank (the size of a large bowl I guess). There are lots of bubbles but no stream from the filter tube, the girl at the pet shop says it's okay since we can see bubbles lining the bowl, is she right?

Also, one of the fish is a black moor. The one I took has only one eye bulging, while the rest I saw had two, is that okay?

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    It is preferred if you can post separate questions instead of combining your questions into one. That way, it helps the people answering your question and also others hunting for at least one of your questions. Thanks! Commented Jan 8, 2017 at 12:16
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    You need at least 50 to 100 l for these fishes. Everything else is animal abuse. The bulging eye can be a sign of intoxication which might result from the living condition. You don't seem to have basic knowledge about how to install an aquarium, so please gather it (using wikibooks.org or a search engine of your trust) before you involve living creatures. Commented Jan 8, 2017 at 12:20
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    Take them back ASAP. Research cycling a tank before bringing home any fish. It takes roughly 30 days for a tank to be suitable for live fish because the bacteria that filters the water takes about 30 days to get established to the point where it can process the waste that live fish produce. The person who sold you all this should be fired if they knew you didn't have a tank setup. Additionally, goldfish, which is what a black moor is, require roughly 30 gallon per fish to thrive. They're a messy large bodies fish. Putting even one of these in a small tank or bowl is going to be a disaster.
    – Jestep
    Commented Jan 9, 2017 at 19:02
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    @Jestep is right, store should have made you aware of cycling the tank before selling you fish. I ran my tank for a month before I put any fish into it. Commented May 18, 2017 at 13:14

1 Answer 1


What kind of filter is it? If it's a sponge filter with an air pump, then indeed you won't see a stream, but lots of bubbles.
However, such filter is not suited for the kind of fish you have. They have limited filtering capacity.
Do you have any information about the type of filter/tank you bought?

Also, perhaps not an answer to your question, but as far as I can tell you've made a few other beginners mistakes:

  • A tank needs to go through a cycling process BEFORE you can add fish to it. This can take at least 4 weeks. If you don't do that, you risk that all your fish will die. Have a look at this answer for more information: https://pets.stackexchange.com/a/323/7038

  • A Black moor is a type of goldfish. For their well being a single goldfish needs at least 60 litres of water (16 gallon). Since you mention that it's basically 'a large bowl', I would assume that your tank is in fact not suitable for any kind of fish, except perhaps a single Betta.

  • Pet stores usually only care about selling things & profit, or they simply don't have decent knowledge about fishkeeping. The fact that they 'allowed' you to buy fish & tank on the same day is already an indication of this. If you want advice, you're better of going to a specialized fish shop for information, or look it up on the internet beforehand (or ask questions here).

  • Since you are already concerned that your fish is not ok, I would try to return them to the store where you bought them. And then do some research on starting & running aquariums and the type of fish you want to keep. It's often thought that goldfishes are easy to keep, and perhaps it also looks like that. But in fact, if you keep them in small fishbowls they usually don't live that long. When kept in a good & healthy environment, a goldfish could live for 20 years or more...

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