Newbie fish parents tend to have this question often: “How many platies in a 29-gallon tank can we safely keep?”

**A 29-gallon tank is ready to hold either 19 male platies or 11 female platies.**

But what were the calculations that we made to get this number? And is it okay to have a mix of both platy sexes in a tank of this size?

This article approaches all these points in-depth, so let’s get to it!

## How Many Platies in a 29-Gallon Tank: How to Calculate the Right Number

It can be tricky to understand the math behind the numbers we’ve just mentioned. I mean, platies are pretty small, so how is it possible you can only have 19 males or 11 females in a 29-gallon tank?

Well, the thing is that one platy requires around two gallons of water to have a healthy and comfortable life in its tank. Or, you can look at it this way:

For every inch of adult platy length, there must be 1 gallon of water in the tank to cater to its needs. This way, you’ll be sure that there’s enough space for your fish to swim, socialize, and go about its day without feeling contained.

Now, since **males are usually 1.5 inches in length, having 19 males adds up to 28.5 inches, which will require 28.5 gallons of water.** So, a 29-gallon tank can do the trick here.

The same goes for females, who are around 2.5 inches in length individually. In a 29-gallon tank, you can only have 11 females since they’ll need 27.5 gallons of water.

### Having a Combination of Male and Female Platies

Of course, you might prefer to have both males and females in the same tank. Thankfully, this isn’t very complicated to calculate as long as you know the size of your fish as adults.

Before determining the suitable number of both, keep in mind that the males have to be significantly fewer than the females. This ensures that the females don’t become overwhelmed and stressed out because of too many mating requests.

Besides, platies breed pretty fast, so you don’t want to end up with issues of overpopulation too soon after bringing your fish home.

A good rule of thumb you can loosely follow here is to provide only a single male for every 3 females in the tank to control the population inside it. With that in mind, here are a few male and female platy you may want to include in your 29-gallon tank:

- 5 males (7.5 inches) and 8 females (20 inches), which equals an overall of 27.5 inches and requires 27.5 gallons of water
- 4 males (6 inches) and 9 females (22.5 inches), which equals an overall of 28.5 inches and requires 28.5 gallons of water
- 3 males (4.5 inches) and 10 females (25 inches), which equals an overall of 29.5 inches and requires 29.5 gallons of water

## What If the Males and Females Come in Bigger Sizes?

Of course, the previous section only mentions the average size of a male and female platy. Sometimes, platies could grow larger than 1.5 inches for the males and 2.5 inches for the females.

In this case, the number of platies we’ve already discussed will change based on the size of the fish you have. Instead of putting 19 males or 11 females in a 29-gallon tank, the numbers will drop so that the tank could house the slightly larger fish.

## What Happens If I Put More Platies Than Necessary in a 29-Gallon Tank?

Having more platies than the required number in a fish tank could lead to countless troublesome situations. An overcrowded tank is never a good idea because it might cause the following:

- The fish will feel anxious and stressed due to limited swimming and hiding areas
- Germs and diseases will spread more easily among platies
- The water quality in the tank will decrease, which will need you to perform maintenance more often
- You might face overpopulation problems in case the tank includes both male and female platies

## What Happens If I Put Fewer Platies Than Necessary in a 29-Gallon Tank?

You might think that having only some platies in a large tank shouldn’t be that bad, right? I mean, the fish will have more freedom to swim as they please and the hiding spots will be more available, so the platies should feel better.

Well, it’s quite the opposite, actually.

See, platies don’t enjoy their solitude, and they prefer to be always surrounded by other platies so that they can swim and eat together. If there are too few platies in a tank, these scenarios are more likely to occur:

- The fish will soon feel lonely, unsatisfied, or even depressed
- The platies might become lazy due to the lack of stimulation
- The fish may have shorter lifespans

All in all, you should know that balance is key to a healthy lifestyle in your platies fish tank. By following the calculations we’ve already discussed, you should be on the safe side!

## Have Another Tank Size You’re Looking for?

How Many Platies in a 5-Gallon Tank?

How Many Platies in a 10-Gallon Tank?

How Many Platies in a 20-Gallon Tank?

How Many Platies in a 55 -Gallon Tank?

## Final Thoughts

How many platies in a 29-gallon tank are good enough for the fish to have an ideal environment to thrive in?

Well, 19 males or 11 females are the right numbers in this case. You could also have a mix of both, but make sure there aren’t more males than females, or it could mess with your aquarium population.

After learning the correct way to calculate the number of platies in a tank, it’s finally time to head over to the store and buy a nice group of platies to start your fish-parenting journey!