All You Need To Know About How Many Tilapia Per Gallon In Your Tank

Last Updated on September 8, 2024 by Sara Rose

Tilapia is an excellent fish choice for your aquaponics system for many reasons.  This article will tell you detailed information on how many tilapia per gallon you need in your tank!  

It will also overview key details about raising tilapia in your aquaponics system.  Tilapia is a versatile fish that can be found all around the world.  Many fish farmers work with tilapia because they are an easy fish to raise.  

If you are considering using tilapia in your system, you made a really good choice.  Tilapia is a good fish for beginner aquaponics systems.

Getting Into Tilapia Aquaponics 

Tilapia aquaponics simply means using tilapia as the fish in your tank.  Excretion from these fish will be pumped into your growing beds to provide your plants with nutrition and water.  

This means you need to keep your tilapia healthy.  The happier the fish are, the better your overall system will function.  

Tilapia are considered low-maintenance fish.  They especially like warmer water, so if you live in a cold climate you may want to avoid these fish or use a water heater. 

Keeping your fish healthy has to do with a variety of different factors.  At its core, you need to keep your tank ecosystem balanced and clean.  

Before you get started, there are a few choices you have to make.  First is your tank size.  This will determine the amount of water your tank holds and how many fish you can raise.

Tilapia Aquaponics Tank Size

To start, assess how much space you have available to build your system.  You will be limited by your location.  Once you have your tank area and growing space mapped out, you can choose how many gallons per tank you need.

If you have enough room, a great starting size for tilapia is around 130 gallons.   This is considered a small size tank.  The measurements for a 130-gallon tank is around 72″ x 18″ x 21″ (Length X Width X Height).  So make sure you have enough space to fit these dimensions.

Of course, the more gallons in your tank means a larger tank size.  Make your plan accordingly.  Once you have decided your tank size you can determine how many tilapia per gallon are in your tank.

Tilapia Aquaponics Tank Size

Learn more about: The Facts About 250 Gallon Fish Tank Dimensions

Figuring Out How Many Tilapia Per Gallon

On average a tilapia can grow to be around 1 pound in weight.  This weight depends on which type of tilapia you choose to raise.  

Mozambique Tilapia can grow between 2-4 pounds and Blue Tilapia can grow between 3-4 pounds.  4 pounds is the maximum weight tilapia will reach.  This is only in certain scenarios where there is an excess of food.  

However, a good number to stick to is one tilapia is around 1 pound.  Make sure to pick the specific variety that is most suitable for your needs. 

A rule you can follow is that one pound of tilapia requires between 3-5 gallons of water.  

So, for 5 tilapia you would need between 15 – 25 gallons of water in your tank.  

If your tilapia are very healthy, they can grow larger than one pound.  Account for this when determining how many tilapia per gallon are in your tank.    If you want to be on the safe side, stick with 1 tilapia per 3 gallons of water.

You do not want to overcrowd your tank.  Overcrowding your tank causes many different problems, but will ultimately result in the death of your fish.  This will require you to restart your whole aquaponics system.  

To avoid this problem, be sure to figure out the exact amount of tilapia your tank can handle. 

If you are a beginner, we recommend starting with around 20 tilapia.  20 is a good number to provide adequate fertilizer for your plants, enough food, and leave some room for error.

Other Considerations

While tilapia are among some of the easiest fish to raise, there are some specific things you will need to know.  First off, depending on the Tilapia variety the diet changes.  The Nile Tilapia are omnivores when they are adults.  

Whereas the Blue Niles are primarily vegetarian once they are adults.  Depending on the variety you choose, you will have to alter their diet.  

Tilapias like to eat a lot.  In fact, you can feed them up to 3 times per day! Pay attention to their eating habits to know how much they really need.  Any uneaten food will make your tank dirty so avoid overfeeding.  

Certain varieties grow faster than others.  The Blue Tilapia grows between 3-4 pounds over a span of 3 years!  So if you plan to eat your fish, you probably will be eating them when they are closer to 1 pound in Year one.  Otherwise, you would have to wait 3 years to consume your fish.

The Mozambique Tilapia grows 2-4 pounds in 1 year.  This will be a faster-growing variety than the blue tilapia.  

However, one of the fastest-growing varieties is the Nile Tilapia which grows 1-2 pounds in 7 months!! For aquaponics doers, this is an ideal selection.  

Tilapias are an exceptionally good choice for aquaponics because they are high waste producers.  The more fish waste means the more fertilizer for your plants.  

The fish grow fast and are very tasty to eat.  In fact, according to the Journal of Aquaculture Research and development, Tilapia is a very healthy fish for humans to eat.  

Now you should know the rules to decide on how many tilapia per gallon is in your tank.  Make sure to observe your fish once they arrive in their new home.  If it seems like they are happy, the fish will remain active and sustain a healthy diet.

If something seems off, try to reduce the amount of fish in the tank or improve the tank conditions.  Don’t be intimidated by this!  Tilapia are very hardy fish as long as you keep a good temperature for them.  Good luck and enjoy the process.


Feel free to comment and ask questions below!

Read more about: How Big Do Tilapia Get In An Aquaponics System

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