Article: Although platy fish don't require a lot of space, it's a good idea to get a bigger tank than you need if you plan on breeding them. That way, as your platy fish start to reproduce and the fry grow into adults, your tank won't get overcrowded. With a tank that's at least 29 gallons (110 L), you'll be able to breed your fish and take your time finding new homes for the adults without the tank getting too crowded.  You can find a large aquarium tank online or at your local pet store. Make sure the tank you get has a secure lid on it since platy fish can jump.  An overcrowded tank can make your fish stressed and more prone to fighting. Not only will a substrate make your aquarium look better and more natural, it will also provide a surface for beneficial bacteria to grow on in the tank. For your platy fish, you can use any kind of aquarium gravel for substrate, but make sure it's clean before adding it to the tank so your fish don't get sick.  To clean your aquarium gravel, rinse it in a sieve over a bucket until the water straining through the sieve runs clear. You can find aquarium gravel online or at your local pet store. Providing shelter is especially important when you're breeding platy fish since the young fry will need places to hide from the adults. Without enough shelter, the young fry may be eaten by your older fish. Also, your adult platy fish will enjoy having some sheltered resting places as well.  Try to use live aquarium plants to replicate the platy fishes' natural environment. Include floating plants in the tank, which make great hiding places for young fry.  You can purchase plastic aquarium shelters, like small plastic caves or hollowed-out logs, online or at your local pet store. Without a filter, the water in the aquarium will become stagnant and dirty, and there won't be enough oxygen for your platy fish to survive. However, make sure you use an air-powered sponge filter since other types of aquarium filters can suck up and kill small fry. You can purchase an air-powered sponge filter at your local pet store, or you can order one online. This is the ideal temperature range for platy fish. Attach a thermometer to the inside of the aquarium so you can monitor the temperature and make adjustments if necessary. While it shouldn't be difficult to keep the water in the tank within this temperature range, you may need to use a heater if the water is too cold.  You can purchase both submersible and hang-on aquarium water heaters online or at your local pet store. Keep in mind that the larger your aquarium, the stronger of a heater you'll need.  For a 29 US gal (110 L) aquarium, you'll need a heater that's between 75 and 200 watts. The colder the room that your aquarium is in, the more watts you'll need.  If you're worried about the water in the tank being too hot, you can buy an aquarium chiller to lower the water temperature. using a limited number of platy fish. Cycling an aquarium is the process of starting a natural nitrogen cycle in the tank, which helps filter out harmful ammonia that kills fish. You can cycle your tank by introducing platy fish to it (the fish will kickstart the biological process), but you should only add 1 fish for every 2–3 gallons (7.6–11.4 L) of water. Then, once the tank has cycled after about 6 weeks, you can add the rest of your platy fish.  For example, if you're using a 29 US gal (110 L) tank, you would introduce 10-14 platy fish into the tank at first. Then, after around 6 weeks, you could add more fish to the tank since the water would be safe enough at that point. Adding too many platy fish before the tank has cycled can put stress on the fishes' bodies and potentially cause them to die. If there are too many male fish in the tank, they might start to fight over the females. Also, an abundance of male fish can stress out your female platy fish, so it's a good idea to have 3 females for every 1 male. Determine the sex of your platy fish when you're buying them and before adding them to your tank since it will be easier than doing it after they're all swimming around in the aquarium together.

What is a summary?
Get an aquarium tank that holds at least 29 gallons (110 L). Line the bottom of the tank with aquarium gravel for a fish-friendly substrate. Add plants and hiding places to the tank so your platy fish have shelter. Set up an air-powered sponge filter in the tank to clean and aerate the water. Keep the tank water at 70–77 °F (21–25 °C). Cycle the water in the aquarium Maintain a 1:3 ratio of male fish to female fish to avoid potential problems.