Growing Prawns In Aquaponics: Your Complete Guide To A Sustainable

Written ByHoward Parker

Have you ever looked at your aquaponics setup—the fish swimming peacefully, the plants thriving—and thought, “What if I could take this ecosystem to the next level?” Maybe you’ve wondered if there’s a way to make it even more productive, more balanced, and frankly, more exciting.

I’m here to tell you there absolutely is. I promise that by the end of this guide, you’ll see how adding freshwater prawns can transform your system from a simple garden into a multi-layered, sustainable food-producing powerhouse. The journey of growing prawns in aquaponics is incredibly rewarding, and it’s more accessible than you might think.

In this complete guide, we’ll walk through everything together. We’ll cover why prawns are a perfect fit for your system, how to choose the right species, setting up their environment for success, and even how to troubleshoot the common hiccups along the way. Let’s dive in and unlock a new dimension of your aquaponics adventure!

Why Add Prawns to Your Aquaponics System? The Surprising Benefits

Integrating prawns isn’t just about adding another creature to your tank; it’s about creating a more robust and dynamic ecosystem. Think of them as the missing piece of the puzzle. Here are some of the incredible benefits of growing prawns in aquaponics that get hobbyists so excited.

They Are Nature’s Cleanup Crew

Prawns are fantastic detritivores, which is a fancy way of saying they eat waste. They will happily scavenge the bottom of your tank for leftover fish food, fish waste, and other organic debris.

This cleaning action helps reduce the buildup of sludge and lessens the load on your filtration system. A cleaner tank means healthier fish, healthier plants, and less manual maintenance for you. It’s a win-win!

A Delicious and Sustainable Food Source

Let’s be honest—one of the biggest draws is the prospect of harvesting your very own fresh, delicious prawns. The taste of homegrown prawns is miles ahead of anything you can buy frozen at the store. This makes for a truly eco-friendly growing prawns in aquaponics system, as you are producing high-quality protein right in your own home with minimal environmental impact.

Increased Biodiversity and System Stability

A more diverse ecosystem is often a more stable one. By adding a bottom-dwelling crustacean, you are filling an ecological niche that was previously empty. This creates a more balanced food web within your tank, contributing to the overall health and resilience of your aquaponics setup. This is a core principle of sustainable growing prawns in aquaponics.

Getting Started: Choosing the Right Prawns and Setting Up Your Tank

Alright, you’re sold on the idea. Now for the fun part: setting things up! This initial phase is crucial, but don’t worry, it’s straightforward. Getting the foundation right is the first step in our growing prawns in aquaponics guide.

Choosing Your Prawn Species

While there are many types of freshwater shrimp and prawns, one species stands head and shoulders above the rest for aquaponics: the Giant Malaysian Prawn, or Macrobrachium rosenbergii.

These prawns are ideal because they grow large, are relatively hardy, and tolerate the typical water conditions found in a healthy aquaponics system. They are the go-to choice for both commercial and hobbyist growers for a reason. You’ll typically buy them as post-larval (PL) juveniles from a hatchery.

Tank Size and System Requirements

Prawns aren’t too demanding, but they do need their space. A good rule of thumb is to allow at least 2 to 5 gallons of water per prawn. So, for a small batch of 20 prawns, you’d want a tank that’s at least 40-100 gallons.

They can be integrated directly into your main fish tank or sump tank. The key is ensuring they have plenty of floor space, as they are bottom-dwellers. A wide, shallow tank is often better than a tall, narrow one.

Creating a Prawn-Friendly Habitat

Prawns need places to hide, especially when they are molting. Molting is the process where they shed their old exoskeleton to grow, and during this time, they are soft and extremely vulnerable to other prawns or fish.

Provide plenty of hiding spots to reduce stress and prevent cannibalism. Here are some great ideas:

  • PVC Pipe Sections: Simple, cheap, and effective. Cut various lengths of 1-2 inch PVC pipe and scatter them on the tank floor.
  • Mesh Netting: Draping plastic mesh or netting vertically in the tank creates complex, multi-layered habitats that prawns love to climb and hide in.
  • Rocks and Driftwood: Create small caves and crevices with inert rocks or aquarium-safe driftwood.

The Heart of the System: Water Parameters and Care Guide

This is where your skills as an aquarist truly shine. Maintaining stable water quality is the most critical factor for success. This growing prawns in aquaponics care guide will help you keep your prawns happy and healthy.

Prawns, like fish, are sensitive to sudden changes. Consistency is your best friend. Here are the key parameters to monitor:

  1. Temperature: Aim for a warm and stable temperature between 78-86°F (25-30°C). This is their ideal range for active growth. An aquarium heater is a must in cooler climates.
  2. pH Level: Keep the pH between 7.0 and 8.5. Prawns prefer slightly alkaline water, which aligns well with many aquaponics systems.
  3. Ammonia and Nitrite: These must be kept at 0 ppm. A fully cycled and mature aquaponics system should have no problem with this, but always monitor, especially after adding new stock.
  4. Nitrate: While less toxic, keep nitrates below 40 ppm. Your plants will be consuming nitrates, but it’s still good to keep an eye on the levels.
  5. Water Hardness (GH/KH): Prawns need calcium and other minerals to build their exoskeletons. A general hardness (GH) of at least 100 ppm is recommended. You can supplement with crushed coral or oyster shells in your filter if your water is too soft.

Following these guidelines is one of the most important growing prawns in aquaponics best practices you can adopt.

Feeding Your Prawns: What, When, and How Much

While prawns are excellent scavengers, you can’t rely on leftovers alone, especially if you want them to grow to a good size. You’ll need to supplement their diet.

Prawns are omnivores. A high-quality sinking pellet with around 30-35% protein is a great staple. You can find commercial prawn or shrimp feeds online. Feed them once or twice a day, preferably in the evening, as they are most active at night.

Only give them what they can consume in a few hours. Overfeeding can foul the water, which is dangerous for both your fish and your prawns. One of the best growing prawns in aquaponics tips I can give is to start with a small amount of food and observe. If it’s all gone quickly, you can add a little more next time. If food is left over, reduce the amount.

Your Step-by-Step Guide to Growing Prawns in Aquaponics

Feeling ready to start? Here is a simple, step-by-step process that breaks down how to growing prawns in aquaponics from start to finish.

  1. Prepare Your Tank: Make sure your aquaponics system is fully cycled, stable, and has been running smoothly for at least a month. Add your substrate (sand or fine gravel is best) and all the hiding places we talked about earlier.
  2. Source Your Prawns: Order your post-larval (PL) prawns from a reputable hatchery. They will arrive as tiny, almost transparent juveniles.
  3. Acclimate Carefully: This is a critical step. Float the bag in your tank for 20-30 minutes to equalize the temperature. Then, slowly add small amounts of your tank water to the bag every 10-15 minutes over the course of an hour. This prevents shock.
  4. Release Your Prawns: Gently release the prawns into the tank. Don’t be surprised if they disappear immediately into the hiding spots you created!
  5. Monitor and Feed: For the next 4-6 months, your job is to monitor water quality daily, maintain a stable temperature, and provide a consistent feeding schedule.
  6. Watch Them Grow: You’ll see them shed their skins (molt) as they grow. Don’t remove the old exoskeletons right away—the prawns will often eat them to reclaim the valuable calcium.

Troubleshooting: Common Problems with Growing Prawns in Aquaponics

Even with the best care, you might run into a few bumps. Don’t panic! Here are some common problems with growing prawns in aquaponics and how to solve them.

Problem: Prawns Are Dying After Molting

This is often called the “white ring of death” and is usually related to water hardness. If your water is too soft (low GH), the prawn may not have enough minerals to form its new shell properly and gets stuck.

Solution: Test your GH. If it’s low, add a source of calcium like crushed coral, oyster shell flour, or a commercial GH booster.

Problem: Aggression and Cannibalism

Prawns, especially the larger males, can be territorial. Cannibalism typically happens when a freshly molted, vulnerable prawn is attacked.

Solution: This is almost always due to a lack of hiding spaces or overcrowding. Add more complex structures like mesh, pipes, or rock piles. Ensure you are not exceeding the recommended stocking density.

Problem: Slow or Stunted Growth

If your prawns aren’t growing, the cause is usually one of three things: temperature, food, or water quality.

Solution: Check your heater to ensure the temperature is consistently in the 78-86°F range. Assess your feeding—are you providing enough high-quality food? Finally, double-check your water parameters to ensure there’s no underlying stress from poor water quality.

Harvest Time! When and How to Harvest Your Homegrown Prawns

After 4-6 months of care, you’ll be rewarded with large, ready-to-eat prawns. They will typically be around 5-8 inches long. You can harvest them all at once by draining the tank, or you can “selectively” harvest the largest ones as needed using a net.

Selective harvesting is often preferred in a continuous aquaponics system. It allows the smaller prawns more time and resources to grow, giving you a more staggered and consistent supply.

Frequently Asked Questions About Growing Prawns in Aquaponics

Can I grow prawns with my existing fish?

Yes, but choose your fish carefully! Prawns do best with peaceful, mid-to-top-dwelling fish like Tilapia, Bluegill, or Guppies. Avoid aggressive bottom-dwellers like cichlids or catfish that might see your prawns as an expensive snack.

How long does it take to grow prawns to a harvestable size?

Starting from post-larval juveniles, it typically takes 4 to 6 months to reach a good “jumbo” harvest size, depending on temperature, diet, and water quality.

Do I need a separate, dedicated tank for prawns?

Not necessarily. Many people successfully raise them in their main fish tank or a large sump tank, provided there are plenty of hiding places and the fish are compatible. A dedicated tank simply makes management and harvesting easier.

What is the biggest mistake beginners make?

The most common mistake is improper acclimation. Prawns are very sensitive to sudden changes in water chemistry and temperature. Rushing the acclimation process is a recipe for disaster. Take your time—an hour of patience can save your entire batch.

Your Aquaponics Adventure Awaits

There you have it—everything you need to get started on the exciting journey of growing prawns in your aquaponics system. It might seem like a lot at first, but it boils down to the same principles you already use: creating a stable, healthy environment and paying attention to your animals’ needs.

Adding prawns transforms your system into a truly integrated ecosystem, providing you with a deeper connection to your food and a delicious, sustainable reward for your efforts. It’s one of the most satisfying projects you can take on as a home aquarist.

So go ahead, find a hatchery, prepare your tank, and get ready to enjoy the incredible experience. Happy growing!

Howard Parker
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