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Number of Platies vs. Tank Gallon Size [Complete GUIDE]

Being an aquarist, you should first have the ideal tank size sufficient for the movement and schooling of platies.

The easily bred and most popular fish for aquariums is the Platy fish. Luckily, platies don’t acquire large tanks for a living but need sufficient space.

Below is some interesting discussion on how many platies can be in a 10-gallon tank.

The number of platies in a 10-gallon tank:

How many platies are in a 10-gallon tank? Platies vary in size from 1.5 inch (Male platty) to 2.5 inches (female platty). If we talk about the female 2.5-inch platty, four to five platies can live in a 10-gallon tank as highly active fish. I recommend using a 10-gallon tank and keeping one inch of platty per gallons, i.e., four female platies and seven male platies in a ten-gallon tank. Maintaining water parameters in small tanks is a very tough job. For the happy survival of fish, more giant tanks are recommended.

Having 15% fewer platies in overcrowded tanks is favorable for avoiding conflicts and stress conditions.

Water QuantityFemale platiesMale Platies
5 gallons24
10 gallons47
20 gallons814
25 gallons1018
30 gallons1221
40 gallons1628
Recommended tank size vs. number of platies

The answer given above is not enough for such a broad topic.

Continue reading about how to make favorable conditions for your platies, the male-to-female ratio in a single tank, adjusting your tank for multiple platies, and much more.

Tank size vs. Number of platies

  • The tank size ideally depends on the size of your fish. For example, an adult Platy fish is 2.5-inch long. So your Platy of 2.5 inches in length would need 2.5 gallons of water.
  • A ten-gallon aquarium can comfortably hold a group of four to five platies.
  • The ideal tank size for platies is 40 gallons, which can accommodate a reasonable number of about 8 platies along with a few more companion fish.
  • My experience indicates that a Platy can survive in a minimum of ten liters of water if the parameters are taken Care of.

How many platies are in a five-gallon tank? As I recommended keeping one inch of Platy per gallons, i.e., a maximum of two platies in a five-gallon tank. But 5 gallon tank is strongly not recommended for platies. Platies dont happly survive in such a small tank.

The ideal size of tank for platies

The ideal tank size for platies is 40 gallons, which can accommodate a reasonable number of about eight female and fourteen male platies, along with a few more companion fish.

Below are some aspects you must remember when selecting the tank for your Platy hobby.

Free space:

Usually, besides the fish, an aquarium is occupied with plants, food, objects that act as hiding places for the platies, a water filter, an air pump, and decoration material.

So you have to remember how much free space for the Platy would be available in the tank after this all stuff.

Drawbacks of small and large tanks:

In small tanks, toxins from Platy waste accumulate more rapidly, which is risky for Platy life.

While in large tanks, platies, especially their fry, become exhausted in search of food as they swim all around the tank. Larger tanks are tough on pockets as well.

The ideal number of platies in the tank:

One Platy per gallon is ideal for smaller tanks like ten gallons.

For larger tanks greater than ten-gallon, one female Platy per two-gallon tank is practical, estimating five female platies per ten-gallon tank.

Male to Female Ratio in a 10-gallon tank

Male Platy-oriented 10-Gallon tank:

If one of your objectives is to make your aquarium more colorful and you have no interest in Platy breeding, you can prefer male platies in your tank. The same rule applies; a maximum of seven male platies in the ten-gallon tank.

Both male and female Platy-oriented 10-gallon tanks:

If you want to have both sexes in your tank, you will follow the 1:2 rule. That is one male and two females, i.e., In the ten-gallon tank, keep a maximum of two males with three females because males chase the female and harass her when she is alone or one in number.

Single Platy in a tank

Platies are schooling fish. They prefer swimming and living in the form of a group. This way, they feel safer and less stressed.

Naturally, platies have little emotion about feeling isolated, but it does deteriorate their health compared to the platies living in a group.

So I advise having platies in your tank in a minimum group of five. (for that, of course, you will need a bigger tank like 10-gallons tank)

Additional Read: Do Guppies Sleep?

Only male platies living together in the 10-gallon tank

Male platies have competing nature. They will constantly compete for food which will cause a fight among them.

Male platies tend to hold territorial disputes as well. If you want to avoid an unfortunate environment, you should keep female platies with male platies in your tank.

Pros and Cons of keeping platies in a small VS large size Gallon tank

1. Tight space

If you live in a small house or have little space, a ten-gallon tank is perfect for carrying with your platy hobby. For large homes, a large-sized tank minimum of twenty-gallon will be preferred.

2. Indoor Aesthetics

Being a colorful fish, Platy will improve your home aesthetics, and all this is set in a low space occupied.

3. Low maintenance

The significant edge of keeping platies in a small tank is the ease of maintenance of this size. Low maintenance will lead to a pleasant environment for your platies to dwell.

4. Aggression

A confined space cause behavioral issues like aggression in the Platy fish. Aggression towards its tank mates is a common problem that attacks other fish. This unfriendly environment inside the tank can lead to Platy’s death. There are no such issues in large-sized tanks.

5. Waste toxin accumulation

Due to less space, more toxins from platy waste accumulate inside the small-sized tank. These toxins disturb the water chemistry.

Dirty aquarium

6. Poor growth

The growth of Platy organs is poor due to the confinement of space. They can’t swim freely because poor growth leads to organ failure and premature death.

Keeping platies in a glass bowl

  • Glass bowls look pleasant aesthetically, but these bowls carry only 2-Gallons of water, which is insufficient space for a Platy to enjoy a happy environment.
  • If even you buy a filter for your glass bowl, it will be useless because it will not get fixed inside the bowl, and limited features will not allow the filter to work correctly.

Taking Care of the platies in a 10-gallon tank

A 10-gallon tank is comparatively a large tank. So to keep your platies alive and happy, you need to take good Care of the tank/water parameters.

1. Plantation

Make sure you have enough plants in your tank to absorb the carbon dioxide, nitrate, and other substances that are toxic waste from the fish excretion.

Platies can survive on their own with just plants and pests. So plantation in the ten-gallon tank is essential.

Plants in Aquarium

2. Water Quality Check

Change the water frequently to eliminate all the toxins. If you have a filter, change the water weekly.

If you do not have a water filter, about 25% of the tank water should be changed daily.

3. Feeding Habit

When feeding your platies, try not to put too much food as it can pollute the water. Stop feeding if they stop eating.

4. Water filter installation

You need a filter that will eliminate the ammonia by changing it to nitrite and then nitrite into a less toxic form called nitrate.
Ensure that The levels of nitrite and ammonia are both 0 ppm and nitrate below 20 ppm, General Hardness 167-567 ppm, and Carbonate hardness 54-90 ppm

(Nitrates are removed when you do the water changes in the tank). This process is called the Nitrogen Cycle.

5. PH Level

Also, make sure to maintain a healthy PH level in the tank. pH level should be between 6.8 to 8.5 inside platy’s tank.Here is how you can

naturally control the PH in your water tank.

6. Temperature

The temperature insdie the tank should be between 18-27oC, Otherwise different heaters should be used to make the temperature normal. Platies cant survive in very high or low temperatures.

Tank Mates of Platies

Rasboras, Cory cat fish, Tetras, Snails, Rainbow fish, Neon Tetras, Mollies, Endlers, Zebra Danios, Bettas, and Swordtails are some kinds of tank mates which can live peacefully with platies.


You can house at most two platies in a three-gallon tank. The fish will survive but won’t be over the moon.

This is because it needs balanced water surroundings, more space to swim around, and is a schooling fish.

The ideal size of tank to be used is ten