How Long Does Guppy Fry Take To Grow And Reach Full Size?

Most of the time, guppy fries face many problems in their early stage of life due to low energy. Mature guppies attack the fries and sometimes tend to eat them. Guppy fry makes a lot of effort to survive and save their lives. So fish breeds are always concerned about how long guppy fry takes to grow and reach full size.

How Long Does Guppy Fry Take To Grow? Usually, it takes four to five months for guppy fries to grow and reach full size with perfect color. At this time, they are adults and fully tail with the ideal body size. They take another two to three months to categorize as parents and for breeding.

Guppy fish need at least seven months to reach full sexual maturity and start reproducing.

How Long Does Guppy Fry Take To Grow And Reach Full Size?

In the below section, we can discuss their growth stages and share some advanced tips to speed up their growth.

If you are a fish breeder, you always consider selling your fish, and the growth rate matters. As an initial step, you can pick fast-growing fries from the breeding tank and move them to a bigger tank. More room tank helps them to grow faster.

After passing the first three months, you can count them as reaching adulthood, which means they are in the younger stage.

Table of Contents

Guppy fry growth stage

Here is the table we can find the guppy fry growth stage more clearly.

Growth stageTime frame
NewbornDays 0-7
JuvenileWeeks 1-4
YoungMonths 1-3
AdultMonths 4-5
MatureMonth 7 -8

Remember that your male guppy fries become slightly more aggressive than female fries. So we recommend moving to a bigger shallow tank to get more room for your guppy fry.

Every guppy fries does not need seven months to reach its full size of growth. Some fries show early development due to their speedy growth.

Growth speed depends on many factors such as feeding, tank size, amount of fries in the tank, airflow, times of feeding, poor tank maintenance, etc.

In the best situation, they grow fast and get the maximum length in a short period, and in the worst case, fries do not produce growth well and look like ill fish.

When you notice such a situation, please do not leave or kill them. You can start feeding them high-protein foods more than three times daily. Do water changes twice a week and provide good airflow to them. You can get good quality mature guppy fries within a few months.

Read More About :- When Do Guppy Fry Get Their Color?

How To Make Guppy Fry Grow Faster?

Proper feeding, enough room with a shallow tank, and perfect water condition make your guppy fry grow faster than you expect.

How To Make Guppy Fry Grow Faster?

We will explain those things below.

  1. Feed high-protein food for your guppy fry

Nutrition food is an essential thing to grow faster. High protein food makes your guppy fry look perfect in shape and bright colors.

Ensure not to feed your baby fries until they pass the first two days. Because the first two days, they are not eating correctly. So you do not need to feed them in the first two days.

Guppy fry starts swimming fast on the third day without hiding in the tank. At that time, you can begin to feed your fries. We will publish a feeding table where you can provide your fries to different ages.

Food TypeGuppy Fry Age
  Infusoria /micro worms First week
  Baby brine shrimp /vinegar eel  From week second to week third 
  Freeze-dried/frozen foods From week fourth to week five
  Tubifex red worms From week six and beyond
  Dry pellets From week eight and beyond

When your guppy fries are born and start swimming well, you can begin feeding them. Fries are tiny, so they can not eat bigger size food. The best way is to start from live feed such as infusoria or micro worms.

Feeding infusoria is an excellent idea because it is much smaller than baby brine shrimp. Fries can quickly chase and hunt this live food, and guppy fries become more active in this kind of activity.

There are many ways to culture infusoria, and do not overfeed it to your fries. It will raise ammonia levels in the breeding tank.

You can start feeding baby brine shrimp to your guppy fries from the second week. Brine shrimp is also high protein food that can help to increase fry’s growth speed.

Newly born guppy fries always need higher protein food for higher growth, so keep feeding them higher quality foods. You can provide four times per day with small quantities and ensure at least two times feed live food. 

Do not overfeed your fries, as it will increase ammonia levels in the tank, and baby guppies will die.

Baby guppies always tend to eat live food, so if you feed pallets of food, make sure they accept it. If fries reject pallets, then pallets will sink into the bottom of the tank and raise the ammonia level quickly.

Read More About :- What Fish Will Eat Guppy Fry?

  1. Arrange a shallow tank with enough space

As a breeder, you should pay attention to the tank’s space because a low-space fish tank causes many problems, such as food fights, low oxygen levels, quick water pollution, etc.

If you have twenty gallons fish tank, you can place 150 baby fries into it. Before placing your fries, ensure your tank is well-cleaned. Apply some methylene blue medicine to destroy fungi and viruses.

Always place your fries in the shallow tanks, this will helps to get a good oxygen amount into the tank. Please don’t buy wide fish tanks because they are hard to handle and maintain due to crossing large distances.

How Deep Should The Water Be For Guppy Fry?

Tiny fish tank
  1. Set the proper water condition with the correct levels

Bad water conditions always harm your guppy fries and slow their growth.

So you should set the correct value of pH level with appreciated temperature.

  • Temperature 28-32° CpH: 7.0-7.5
  • Nitrates: <20 ppm
  • Ammonia: 0 ppm  
  • Hardness: 2-20 dGH

Always use a test kit to test the water condition, and arrange the heater to continue the temperature level.

Ammonia is the most critical thing you always need to pay attention to. So keep checking your guppy fry tank ammonia level, and don’t let it increase.

Do not increase or decrease temperature drastically. This will increase stress, and your guppy fries will lead to death.

  1. Do water changes right time

When you feed several times a day, ammonia will rise slowly. As well as, when you provide food, they only eat a few, and remain food start to sink and stay at the bottom of the tank.

Those things can raise ammonia and nitrate levels in the fish tank and directly affect the guppy fish fry’s life span. You can place a filter to control the situation.

The problem is the filter also cannot handle the entire situation of water pollution in the tank. Even if you have set up the quality brand filter, your fish tank needs water changes.

To reduce ammonia affection, you should replace up to 25% of the water in the fish tank.

You need to perform this once each seven days. Always use stock-age water for your guppy fries tanks.

  1. Control the daylight

Refrain from allowing high contrast lighting to the fish tank because it increases the fish’s water temperature and stress level. Baby guppies can’t face the high temperature, and they will suddenly swim to the bottom of the tank. 

This will not be good for their life because lower oxygen amounts in the bottom of the tank and fries face the breathing problem soon.

On the other hand, sunlight increase algae level in the fish tank. Algae will rapidly spread if sunlight point to the tank.

So cover your breeding fish tank from direct sunlight and control the heat. You can place your fish tank under the trees, which will help prevent direct sunlight.

Make Guppy Fry Grow


Guppy fries quickly reach the full size when they get higher protein foods. Some guppies grow quicker, and some guppy fries grow slowly. The maximum time is seven months, but all fries do not take the same time.

In the proper condition, they will mature once they pass seven months, and then they are ready to reproduce.

If you have no plan to reproduce, ensure to separate male and female fish at this age. 

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