How Many Guppies in 10 Gallon Aquarium?

Topic: I’m a beginner to keeping pet fish and my guppy tank is my first tank. How many guppy fish can I keep in my 10 gallon tank? It seems like the guppies are so small that I could keep a lot of them. I’m excited to call these fish my very own pet. Even though they are fish, they still mean a lot to me. I need some help from an experienced fish keeper. Or what about another type of fish?

*Awarded Answer
Posted by Kelly D:

For an experienced fish keeper, I would say you could keep anywhere from 15-20 guppies in 10 gallons of water. But because your a beginner, I would advise starting small. Test yourself to keep just two guppies alive for 4 months and go from there. Guppies give birth at a very rapid pace and chances are you will have babies very quickly. A female guppy can give birth three different times using the same sperm from the male.

If you figure the general rule of thumb of 1 inch of fish per every gallon of water… that puts you at around 5-8 guppies. The waste given off from guppies is very minimal so people get away by having large schools of fish in smaller areas. It’s common for fish aquariums to be overly crowded. As long as water parameters are kept healthy, the fish will do fine.

-Side Note: It seems cool to populate a new aquarium with lots of fish but as a beginner it’s easy to make mistakes. 90% of people that try to keep pet fish drop the hobby within 1 year due to their fish dying. Facts like that show you just how misinformed we are about taking care of our pet fish. Just a heads up to maybe take it slow with 4-5 fish to start. I hope your fish do great and you fall in love with this hobby like most of us do. Fish aquariums are so addicting!

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Posted by Derrik V:
What also makes a difference is what size the guppy are. If they are really young juveniles that are 1 inch long then you can have a lot more of them. The bio-load of younger ones is very minimal. I’ve seen tanks with 100 fry inside of a 10 gallon tank that do just fine. With small fry you have to watch the intake tube on your filtration system. Smaller fish find themselves getting sucked into the intake tube.

Posted by Brandi K:
You will realize that after owning live bearers like these fish.. you will end up with lots more within months. They multiply like rabbits and never stop. Mollies and such will eat their newly born so it somewhat helps even out the high numbers. What most people do is have a lot of floating plants and these plants give the newly born fry a place to hide from their parents of getting eaten (and other fish that eat them). Newly born fry are very tasty to other fish so you really have to watch it if you plan on keeping the babies. The whole process is sort of devastating but.. you can’t really do much about it. Mother Nature is a mean beast sometimes..

Posted by Darrel N:
Babies will be multiplying like crazy and that’s a promise. Especially if you have the water parameters good and the temp right and only guppies in your tank. When there are no roommates that put a little stress on them, they will really feel comfortable and breed. I enjoy watching them and if my tanks get too out of hand I simply feed the new fry in my goldfish tank. Sometimes you literally have to try to get rid of fry because people don’t have room for them. I called my pet store to see if they would take them but they won’t. I couldn’t even give them away for free!