Platy Care Guide: Tank, Feeding & Breeding

What are platies?

Platies, more specifically the Southern Platyfish (Xiphophorus maculatus), is a species of tropical fish in the livebearer family, meaning it is related to Mollies and Guppies, with its closest relative being the Swordtail.

There are a few different groupings of Platy, the two main types being the Southern Platy and the Variable or Variatus Platy.

Variatus Platies are from a different area than your standard Southern Platy and thus have slightly different needs when it comes to temperature.

The variety of Platy we will be discussing in this article is the Southern Platy, which is the tropical species.

Where are platies from?

Southern Platies are found in a few places around the world, but their narrative habitat is southern parts of North America, Mexico and within Central America.

Like their other livebearer relatives however, they are invasive in a multitude of places, including Australia and parts of Asia, largely due to the fact that irresponsible pet owners release them into the wild.

The Platies you will find in your local fish store however, will have likely been bred in an aquarium or man made pond, as they have been domesticated and selectively bred into all different colours and strains.

Water parameters for Platies

Members of the livebearer family seem to often enjoy the same water parameters, with only slight variation. One thing that stays true in most livebearers is the need for a high calcium content to be present in the water.

Platies, much like Guppies, Mollies and Swordtails need hard alkali water to be able to survive.

Although Platies tend to be very tolerable in a wide range of parameters, they will always do better in water with a moderate to high hardness level.

Through keeping and breeding Platies for years, the best water parameters we have found are as follows:

In the wild, Platies are often exposed to some level of sea water, which gives their habitat slightly saline water.

Salt can be used in the aquarium in small doses and can be beneficial as it prevents disease and simulates their natural environment.

However, it is not always necessary and domestic Platies will often live perfectly fine in true fresh water.

Feeding and diet of Platies

Platies are omnivorous fish, consuming both plant and animal species, as well as some types of fungus and bacteria which grow naturally on driftwood and other surfaces.

However, Platies are a fish that swings more towards herbivory, and prefer a diet with a higher plant matter content.

The majority of their natural diet is taken up by soft hair and diatom algae which grows along surfaces in their natural ecosystem.

The best types of foods to give Platies in the home aquarium are algae, veggie and spirulina based foods.

Foods like algae wafers, canned green beans, boiled cucumber or zucchini are great foods to provide them with natural fibres and nutrients.

Best tank mates for Platies

Platies make good tank mates for a wide range of tropical fish and due to their relatively peaceful nature, they can live with most small peaceful tropical fish.

Platies also have quite a large bulky body, short fins and are fast, meaning that they can also be housed with some of the larger and more boisterous tropical fish available in the hobby.

Many fish make great companions with Platies, however, others do not do so well for various reasons.

In this list we will give examples of some of the best tankmates for the Southern Platyfish:

Corydoras

Cory Cats make great tank mates for Platies; they spend most of their time at the bottom of the tank, out of the way. They are peaceful yet are armoured and can hold their own against attack, and are adaptable to a wide range of water parameters.

If you decide to keep Cory Cats and Platies together, you will need to adjust the water slightly so that your tank accommodates for both species; as while they can live together, they come from different environments.

You need to achieve a balance between the two species’ preferred water conditions, where both fish will be comfortable.

For keeping Cory Cats and Platy Fish together, keep the pH at around 7.0 – 7.6 and keep the hardness at a moderate level.

If you like to keep your platies in slightly brackish water, we would suggest switching them over to true freshwater, as Catfish do not tend to do well with salt.

Angelfish

Yes, it is possible to house Angelfish with Platies, as their large size and quick movement prevents them from being easily bullied by Angels.

This is only doable however in a large tank, around 50 gallons or so, to provide enough space for both the Angelfish and the Platies to have their own territories.

Both fish feed from the upper level of the tank and so long as there is plenty of cover and plant life, they will cohabit very well.

To keep them together, you should have your pH sit around 7.0 – 7.6 and maintain a moderate hardness level.

Guppy

Platies and Guppies are commonly kept together as they have very similar care needs. They both like hard water, both have the same diet and same temperament and have the same life cycle.

You could actually breed Guppies and Platies in the same aquarium! Since they belong to a different genus, there is no risk of your Platies and Guppies interbreeding and creating a mule or hybrid fish.

Ricefish

Ricefish are another small community fish that do well with Platies. They prefer similar water parameters, and some species of Ricefish even appreciate a small level of salt in the water, much like the Platyfish.

Most of them tend to prefer cooler waters however, so if you plan to keep them with Platinum or Japanese Ricefish, keep the temperature on the lower end, at around 24C / 75F.

Harlequin Rasboras

Harlequins are also good tankmates to keep with Southern Platies. They are hardy, peaceful and large enough to not be bullied or swallowed.

They prefer softer water however, so if you plan on keeping them together, you should aim to keep your pH from around 7.0 – 7.6 and keep your hardness level moderate. They also like to stay in schools so you need to keep a few of them, which ideally means a larger tank.

They should cohabit well in a 20 gallon, keep around 6 Harlequins and maybe 5-6 Platies.

How to breed Platies

Platies bare live young, which makes them very easy to breed. In fact, a lot of people who have bred Platies usually have done it by accident.

Platies are ovoviviparous fish, meaning that the eggs are fertilised inside the female’s body and stay there until they hatch and develop into free swimming fry.

To breed them, one needs to have the ideal water parameters for the fish to be comfortable, needs to feed them well and provide them with plenty of cover and hiding places.

The next step is making sure that you definitely have male and female fish. To find out the sex of your fish, there are a few key signals to look for.

How to sex Platies

Platies are generally described as being sexually monomorphic – this means that both male and female look the same and it is hard to tell them apart.

However, if you look closer, there are some subtle differences that help you distinguish what is male and what is female.

Like other members of its livebearer family, Platies have larger females than males. 

• Females tend to be bigger, more bulky and have more girth to them, whereas males are smaller, more slender and sleek.

The main way to determine the sex of a platy is to look at its anal fin (this is the fin located underneath, just before where the tail begins).

In males, this fin looks like a spearhead. It is elongated and narrow, you may see them bend it forward or aim it towards a female they are pursuing and this is what they use to mate.

This rod is called the gonopodium and it is used to inseminate a female with a ball of sperm. Only males have these and they develop them at around 6 – 8 weeks of age, depending on the water temperature.

In females, the anal fin is typical of most pelagic fish and is a broad triangle shape.

Rationing Platies

In the wild, Platies don’t have very long to live. Typically they only last around 18 months and are lucky if they see their second year. This means that they need to pass on their genetics quickly, and the instinct to do this in male Platies is strong.

Male Platies are competitive and determined when it comes to breeding, and they will attempt to mate with as many females as possible while deterring other males from doing the same.

In an aquarium, male Platy Fish will spend a large amount of time chasing around females – over prolonged periods, this can cause stress in the females.

To avoid this stress, it is best to house more females than males so that the focus is distributed.

A ratio of 1:2 is good to reduce stress.

Spawning and fry of Platies

Once your fish have mated and the females eggs fertilised, she will then hold on to them for around a month or so. Depending on the temperature, this time could increase or decrease.

Once the eggs hatch inside her, they will develop past the wiggler stage and into free-swimming fry. Once released, they will be well developed and be able to manoeuvre their way out of danger.

They will still have a yolk sack for the next 3 days and after that, they are to find their own food, which is pretty much anything small enough to fit in their mouths.

Platy fry are easy to raise on crushed flake food.

One issue that opposes the breeding of Platyfish is the fact that the parents will often predate on their own young once they are born, so either the young have to be separated, or you need to provide enough cover so that the babies can get away from the parents while they grow.

Before deciding to breed and raise an army of Platies however, you need to have a plan on what you want to do with them. 

• Do you aim to sell them? 
• Do you have enough space to accommodate them all? 
• Is there someone who can take some once they are fully grown?

Before breeding any animal, you need to know what you are going to do with the offspring before you help create new life and have no idea what to do about it.

What tank size do Platies need?

The minimum tank size for Platy Fish is a 10 gallon aquarium, which will allow you to keep 2 or 3 of them.

However, as the males mature you may run into territory issues if there isn’t enough cover for them to hide.

For this reason, the ideal space we recommend keeping platies in would be a 20 gallon long tank.

This provides them with enough territory and enables you to keep a decent number of them.

Platies will do much better in larger tanks, where they can breed and live in greater numbers. 20, 30 or 40 gallon tanks will allow your fish to truly thrive.

What plants are best with Platies?

Platies tend to be more varied in their diet than their relatives and will often pick at soft leaved plants every so often.

If they do this, it is usually because their diet is lacking in plant material and they require additional veggie or algae based foods.

However, if you want your plants to survive, then you need to house plants that are distasteful or are strong enough to not be shredded.

Here are some good examples of plants which are resistant to being consumed by Platyfish:

• Java Fern
• Anubias Barteri
• Jungle Val
• Pygmy Chain Sword
• Moneywort
• Bacopa
• Anubias Nana Petite

Tips and tricks for Platy care

A big piece of advice on keeping Platy Fish in good health is to provide them with a varied diet, but one which consists of plenty of plant material; not just in dry foods, but also in fresh vegetables like cucumber, broccoli, spinach and green beans.

These foods provide Platies with vital nutrients they need to stay healthy, and you will find that keeping your fish on a more herbivorous diet assists in their growth and colour as they become fitter and stronger.

Additionally, buffering your water with KH and a small amount of marine salt can help keep fungus and disease away from your Platies as they benefit from the mineral contents.