How Many Guppies Can You Keep in a 10 Gallon Fish Tank?

Guppy lovers, especially those that want to start keeping the fish most times, worry about the size of water in the fish tank or the number of guppies in an aquarium.

You can keep 1 inch of fish for each one gallon of water.  The average size of a adult guppy is 1 inch to 1.5 inch, so in a 10 gallon tank you can keep 7 – 10 guppies.

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How Many Guppies in 10 Gallon Fish Tank

How Many Guppies Can You Have In A 10-Gallon Tank?

There is a rule most aquarium owners use, the rule is short and straightforward, and it says one-inch size of fish for one gallon of water.

With this calculation, you can determine the number of guppy fish that should be in an aquarium.

This law has an exception; it is evident that if there are ten gallons capacity aquarium.

You can’t have ten gallons of water in it due to other materials in the pond like heater, gravel, sponge (internal) filter, plants, and other decorations that usually occupy space in the aquarium.

For instance, a ten-gallon aquarium will not contain more than seven to eight gallons of the volume of water.

If you stock adult fish of around 1.5 inches in body size apart from the tail region, then only seven adult guppies can be stock in such aquarium.

If you do the calculation, seven guppies multiply by 1.5 inches size will give you 6.66, which is almost the volume of water we said is suitable for ten-gallon capacity aquarium.

Ten guppies per gallons are advisable, but it is okay if the amount of water is not more than seven gallons due to other materials present in the aquarium.


Can I Breed Guppies In A 10-Gallon Tank

Yes, you can, but it is recommended you follow the rule. One inch size of guppy to one gallon of water, but do everything to avoid overcrowding in the aquarium.

Though below are what to do to prevent overcrowding.

You can also stock guppies that are bigger than 1 inch in an aquarium filled with 10 gallons of water if you follow this guide.

i) Ensure you have an internal filter or a good external filter.

ii) Get a standard bio filter media for filtering.

iii) You must ensure there’s fast-growing plant in your tank/aquarium

iv) Make changing water once in a week your habit. Change at least 40% of the water

How Do I Prevent Overcrowding In My Guppy Aquarium

i) Ensure you have an internal filter or a good external filter: If you have purchased an aquarium kit before then, you should know this.

Though filters are in different sizes, there are some meant for 10-gallon tanks while there are some filters for bigger or overcrowded tanks.

If you need the better performance of your guppies and a filter of higher flow rate, then get a bigger internal filter for your aquarium.

External filter does not take space in an aquarium, and if you choose this, you can increase your water volume because it helps create more space.

Other filters can be used in a 30-gallon aquarium or a full tank, but you should look out for a capacity of 125 GPH (470L/hr).

Incase your guppies are in a tank with cover/lid, the external filter is recommended; most of them have a capacity of 100 GPH (400L/hr) while it consumes 6W in twenty-four hours.

ii) Get a standard biofilter media for filtering: Most people that rear guppies overstock the aquarium, due to how fast guppies reproduce and there might not be enough tank/aquarium to put them.

Whenever you have real overstocking, then think biofilter media because sponge filter media will be overwhelmed.

Though you don’t need to stop using sponge filters, you need to add biological filter media that will give a platform for bacteria in the aquarium to help decompose dangerous toxins like ammonia and nitrate in the tank/aquarium.

When searching for a biofilter media, ensure it gives adequate surface area for bacteria in your aquarium.

iii) You must ensure there’s fast-growing plant in your tank/aquarium: Aquarium Water with good quality always have the presence of live plants, do I need to tell you that plants also decorate the aquarium.

If you have 10 gallons of water in a tank and there is no live plant to consume harmful toxins caused by the waste of overfeeding or fish in the tank.

I will give examples of rapid growing live plants to use in your pond.

They are listed below

Amazon sword
The Amazon frogbit
The popular Guppy grass
Americans Elodea popularly called waterweed
Water lettuce
Java ferns

It is no news plant helps eradicate the proliferation of algae in your guppy tank. You must note that plants require water according to photosynthesis and our experience in the field.

Ensure you have at least seven hours of natural illumination of sunlight or other light in your aquarium daily.

If there’s no light in your tank, then the live plants will wither gradually, and the gallons of water in your pons become polluted.

You Might Want To Ask How Many Male Guppies Can Fit In A Ten Gallons Fish Tank?

There should not be more than one male and two female guppies in a ten-gallon aquarium. The first reason is that male guppies are always aggressive to each other, especially in a relatively small tank.

The other part is an increased level of reproduction if you stock more than two females in a ten-gallon aquarium.


Then you must be ready to welcome a lot of fries within the first month, but the presence of females in the aquarium will lower the fight of the males if they are more than one.

In case you don’t have enough tank/aquarium and you want to stock more than one male in a ten-gallon size aquarium, ensure you create hiding spots because it will reduce aggression rates.

I believe you have learned something new from this post, and you now know all about the number of guppies that should be kept in a ten (10) gallon aquarium alongside the merits and the demerits of stocking guppies in such size of the tank.

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