Platies are small, so you may think you can keep many of them in a 10-gallon tank. However, these fish are so active and have such big appetites, this assumption isn’t true.
To keep your platies comfortable in a 10-gallon tank, aim for a group of five fish. This way, the platies will have the security of a small group without feeling like they have to compete for food and space.
How Many Platys Should Be Kept Together?
Platies should be kept in a group of three to six fish. Why? Because platies are shoaling fish.
Are Platies Schooling Fish?
Contrary to popular belief, platies are not schooling fish.
Rather, they are shoaling fish, which means they hang out together for social reasons, but they don’t usually school (swim in the same direction in a coordinated manner).
For this reason, you should keep platies in a small group of about three to six.
If you add more platies, the males of the group could get nippy. Seasoned fish keepers have noticed that platies tend to fight in groups of seven or more.
Platy Social Groups
Ideally, you should keep platie in a group of three to six, so they can form a pecking order. Make sure to keep at least two females for each male platy, otherwise, they could feel pressured to fight for mates.
Although a male and female platy can form a pair, the male may harass the female. Plus, platies do better when they can establish some fishy politics.
All this to say, a social group of three (two females and one male) may be better, and a group of four (three females and one male) may be the best.
Many fish keepers prefer a group of four with three females and one male to make sure each female gets a chance to rest. After all, a platyfish’s favorite activity is breeding.
What Is the Minimum Tank Size for Platyfish?
Each platyfish needs at least two gallons of water, and you should keep a group of at least three fish. By this math, the minimum tank size for platyfish is about six gallons.
Unfortunately, pet stores don’t usually sell 6-gallon fish tanks, so you may need to make a 5-gallon or 5.5-gallon tank work.
Your fish may be able to survive in a tank this small, but they won’t be able to thrive. Additionally, you may run into problems when your fish start to reproduce.
Ultimately, experts agree that a 10-gallon tank size is the best for an appropriately sized group of platyfish. Ideally, you should have 20 gallons or more.
How Many Platies Can Live in a 5-Gallon Tank?
Two female platies or two female platies and one male platy can live in a 5-gallon tank, but it’s not ideal.
If possible, invest in a 10-gallon tank. Not only will your duo or group of three platies be more comfortable, but you can expand to keep a group of five fish.
Can Platies Live in a 6 Gallon Tank?
Yes, three platies can live comfortably in a 6-gallon tank because each platy will have just enough space. Remember, bigger is always better for these active fish!
How Many Platies Are Right for a Gallon?
Zero! Each platy needs at least two gallons of space, and platies should be kept in groups of at least three.
One platy will get lonely on its own, and two platies could harass one another and cause problems.
Can I Keep Platies in a 3-Gallon Tank?
In other words, a 3-gallon tank or anything smaller is much too small for platyfish. The only exception might be a 3-gallon fry tank, but even then, bigger is better.
You cannot keep platies in a 3-gallon tank!
What If You Have an Even Bigger Tank?
A small group of platies will always appreciate more room to explore and eat. Interestingly, if your tank is big enough, your platies may form more than one social group.
How Many Platies Can You Keep in a 20-Gallon Tank?
You can keep up to eight platies in a 20-gallon tank, but keep in mind that platy politics don’t work quite as well in groups larger than seven.
Keep an eye out for fish bullying. Better yet, keep a group of six platies and some tank mates (more on this later).
How Many Platies Can You Keep in a 30-Gallon Tank?
With 30 gallons of space, your platies can form distinct social groups and avoid infighting. You can comfortably keep 12 platies in a 30-gallon tank.
Expect them to form their own little social groups, and give them plenty of food and hiding places, so the groups don’t have to compete.
How Many Platies Can You Keep in a 40, 55, or 60-Gallon Tank?
If you have a very large tank, you can keep up to 18 platies. Otherwise, the social groups may start to fight, and you may have a platyfish production of Romeo and Juliet on your hands.
Instead of adding more platies at this size, you should consider some tank mates.
Tank Mates for Platyfish
Zebrafish, tetras, Harlequin rasboras, and Bristlenose plecos make excellent tank mates for platyfish. Avoid keeping your platies with large or aggressive fish, as well as other livebearers, like guppies and mollies.
Tank mates should only be introduced when you’re sure your platies have enough room. Do not choose other fish that like to swim in the middle of the tank, and make sure your platies get plenty of food and have room to hide.
One of the reasons Bristlenose plecos make great tank mates are that plecos swim at the bottom of the tank and eat sinking food, so they will have more than enough space – and they won’t have to deal with your hungry platies!
What Happens If You Put Too Many Platies in a Tank?
If you put too many platies in a tank, you will have problems with overcrowding.
Your fish may harass each other, and you will have a harder time cleaning and cycling your tank.
Further, your fish will reproduce quickly, which will only worsen your overpopulation problems. This could lead to poor water quality and stress amongst your fishy friends.
Low-quality water looks bad, smells bad, and can stunt your platy fish’s growth.
Worst case scenario, putting too many platies in a tank could lead to the crash of your tank’s nitrogen cycle and ammonia poisoning in your fish.
Enjoy Your Happy Platies!
Keeping five platyfish in a 10-gallon tank is a recipe for success. If you want to keep tank mates, increase your tank to 20 gallons.
Make sure each fish has two gallons of space, and keep two to three female platys for every male. Give your fish plenty of room, food, and places to hide and avoid overcrowding your tank.
Platies are smart, active fish that are extremely fun to watch. They are also peaceful fish that can contribute to a community aquarium with other small, peaceful fish – preferably fish that swim and eat in different parts of your tank.
We hope you enjoyed this blog, and we know you will enjoy your happy platy fish if you stick to the ratios we discussed.