What Can You Grow In Hydroponics – A Guide To Nutrient-Rich Plants

Written ByHoward Parker

Let’s be honest, we’ve all been there. You test your aquarium water, see that nitrate level creeping up, and sigh, knowing another water change is just around the corner. It’s a constant cycle in our beloved hobby—managing waste to keep our fish healthy.

But what if I told you that fish “waste” is actually liquid gold? What if you could turn that nitrate-rich water into a lush, thriving garden that sits right on top of your aquarium, purifying the water as it grows?

This is the magic of combining your aquarium with hydroponics, a practice often called aquaponics. It’s a game-changer. In this complete guide, we’ll explore what can you grow in hydroponics using your fish tank, turning your aquarium into a beautiful, self-sustaining ecosystem. Get ready to discover the best plants, simple setup methods, and all the tips you need to succeed.

What is Aquaponics? Your Aquarium’s Hydroponic Superpower

Before we dive into the plants, let’s clear up one thing. When we talk about growing plants with an aquarium, we’re talking about aquaponics. Think of it as a special, organic type of hydroponics.

In traditional hydroponics, you grow plants in water and add chemical fertilizers. In aquaponics, your fish provide the fertilizer! Here’s the simple, beautiful cycle:

  1. Your fish produce waste, which is rich in ammonia.
  2. Beneficial bacteria in your tank (the same ones from your nitrogen cycle) convert that ammonia into nitrates.
  3. Instead of removing nitrates with water changes, you pump that water to your plants.
  4. The plants eagerly absorb the nitrates as food, grow strong, and send clean, purified water back to your fish.

It’s a perfect partnership. This creates a truly sustainable what can you grow in hydroponics system that’s not only efficient but also incredibly rewarding. You get a healthier aquarium and fresh plants—a true win-win.

The Best Leafy Greens and Herbs to Grow in Your Aquarium System

Ready for the fun part? Let’s talk about the amazing edibles you can grow. For most standard aquarium setups, the best plants to start with are those that love nitrogen and don’t require intense nutrients to fruit. This makes leafy greens and herbs the superstars of aquaponics.

Fast-Growing Leafy Greens

These plants are fantastic for beginners because they grow quickly, giving you fast results and a confidence boost. Their nutrient demands are a perfect match for a well-stocked community fish tank.

  • Lettuce: Varieties like Butterhead, Romaine, and loose-leaf types are champions. They sprout quickly and you can often harvest outer leaves continuously while the plant keeps producing.
  • Spinach: A nutrient-packed green that thrives in the cool, moist environment of an aquaponic system. It’s a bit more sensitive to temperature, so keep it away from hot lights.
  • Kale: Incredibly hardy and packed with vitamins. Kale loves the consistent supply of nutrients from your tank and can be harvested leaf by leaf for weeks.
  • Swiss Chard: Beautiful and delicious! The colorful stems of Swiss chard look amazing growing on top of a tank, and it’s just as easy to grow as lettuce.

Aromatic Herbs

There is nothing quite like snipping fresh herbs for your dinner right from your aquarium. Many common herbs grow like weeds in an aquaponic setup, making them an excellent choice.

  • Basil: This is arguably the king of aquaponic herbs. It absolutely loves water and nitrogen, growing into a lush, fragrant bush. A healthy aquarium can produce more basil than you’ll know what to do with!
  • Mint: Spearmint, peppermint, even chocolate mint—they all thrive. A small pro-tip from experience: mint’s roots can be aggressive and take over, so it’s wise to give it its own container or net pot.
  • Parsley: Both curly and flat-leaf varieties do wonderfully. They are steady growers that will provide you with a continuous supply for garnishing.
  • Cilantro: For those who love it, cilantro is a great choice. It grows fast but can be prone to “bolting” (flowering) if it gets too warm, so keep an eye on your lighting temperature.

Beyond the Salad Bowl: Houseplants That Thrive in Aquaponics

Maybe you’re less interested in a harvest and more in creating a stunning visual display. You’re in luck! Many common houseplants absolutely flourish with their roots dangling in an aquarium, creating a beautiful, jungle-like feel.

This is also the easiest way to start. You don’t need a full setup—just let their roots grow in the tank water!

The Classics: Pothos and Philodendron

If you’re looking for something nearly foolproof, look no further. These vining plants are famous for being incredibly resilient, and they are masters at sucking up nitrates.

Simply take a cutting, place it in the water (or in your filter’s media basket), and watch it go. The roots will grow down into the tank, and the vines will trail beautifully around it. They are one of the best practices for natural nitrate reduction.

Unique and Beautiful Options

Want to try something a little different? These houseplants also adapt wonderfully to having their roots submerged.

  • Peace Lily: Known for its ability to flower in lower light, the Peace Lily is a fantastic choice. Its roots create a dense network that fish love to explore. Just make sure the main crown of the plant stays above water.
  • Spider Plant: These are great because they produce little “spiderettes” that you can easily snip off and place in your system to propagate new plants.
  • Lucky Bamboo: While not a true bamboo, this plant is perfect for aquaponics. You can submerge its roots and lower stalk, and it will grow tall and add a unique vertical element to your setup.

How To Set Up Your System: A Simple What Can You Grow in Hydroponics Guide

Feeling inspired? Getting started is easier than you think. You don’t need a fancy, expensive kit. This simple how to what can you grow in hydroponics guide will get you going with a basic DIY setup.

Step 1: Choosing Your Method

For beginners, simplicity is key. Here are two easy methods:

  1. The Lid Method: The simplest approach. Get a plastic lid for your aquarium (or a piece of styrofoam) and cut 2-3 inch holes in it. Place your plants in net pots (small plastic baskets for hydroponics) that fit snugly into the holes, allowing the roots to dangle into the water.
  2. The Hang-on-Back Method: Repurpose a hang-on-back breeder box or even an old filter. Fill it with a grow medium and place your plant inside. The water from the tank will naturally circulate through it, feeding the plant.

Step 2: Selecting Your Grow Media

Your plants need something to anchor their roots. You can’t use soil, as it will cloud your tank and cause a mess. Instead, use an inert grow medium.

LECA (Lightweight Expanded Clay Aggregate) is the most popular choice. These little clay pebbles provide excellent support and aeration for roots. Always rinse your grow media thoroughly before use to remove any dust.

Step 3: Lighting is Everything

This is a crucial step many people miss. Your standard aquarium light is designed to penetrate water and illuminate your fish—it’s often not the right spectrum or intensity for growing healthy terrestrial plants.

You’ll need a separate, dedicated grow light for your plants. A simple, full-spectrum LED clip-on lamp positioned a few inches above the leaves is perfect for herbs and lettuce. Don’t worry—these are affordable and easy to find online.

The Amazing Benefits of What Can You Grow in Hydroponics (Aquaponics)

Still on the fence? Let’s quickly recap the incredible benefits of what can you grow in hydroponics by partnering with your aquarium. It’s more than just a cool project; it’s a smarter way to run your tank.

  • Pristine Water Quality: The plants act as powerful, natural filters. They eagerly consume the nitrates that are harmful to your fish, keeping your water exceptionally clean.
  • Fewer Water Changes: With your plants handling nitrate removal, you’ll find your water parameters stay stable for much longer. This means less maintenance and heavy lifting for you!
  • Happy, Healthy Fish: Stable water quality is the key to reducing fish stress and preventing disease. Your aquatic pets will be healthier and more vibrant in their clean environment.
  • Sustainable and Eco-Friendly: You’re creating a miniature, symbiotic ecosystem. This eco-friendly what can you grow in hydroponics method reduces water waste and eliminates the need for chemical fertilizers.
  • A Free Harvest: Imagine fresh, organic basil for your pasta or crisp lettuce for a salad, grown right in your living room. It doesn’t get any more local than that!

Avoiding Common Problems with What Can You Grow in Hydroponics

Like any new project, you might face a few bumps in the road. Don’t worry! Here’s a look at some common problems with what can you grow in hydroponics and how to easily solve them. This care guide will keep you on track.

Nutrient Deficiencies

Sometimes, you might see yellowing leaves or slow growth. This usually points to a lack of specific nutrients that your fish waste doesn’t provide in high quantities, like iron.

Solution: First, ensure your tank is properly stocked and your fish are well-fed. If the problem persists, you can add an aquarium-safe iron supplement. Just be sure to follow the dosing instructions carefully.

Pests on Your Plants

Aphids or spider mites can occasionally find their way to your indoor garden. It’s tempting to grab a pesticide spray, but STOP!

Solution: Never, ever use traditional pesticides. They are highly toxic to your fish and will wipe out your tank. Instead, gently wipe the pests off with a damp cloth or introduce beneficial insects like ladybugs if the setup is large enough.

Algae Growth

Algae and plants compete for the same nutrients. If your grow light is spilling into the aquarium, you might trigger an algae bloom in the tank.

Solution: Position your grow light so it only illuminates the plants, not the water. You can create a simple light shield with a piece of cardboard to block any spillage. Keeping the water surface agitated with a filter outflow also helps.

Frequently Asked Questions About Growing Plants with Your Aquarium

Can I grow fruiting plants like tomatoes or peppers?

While it’s technically possible, it’s very challenging for a typical aquarium setup. Fruiting plants are extremely “hungry” and require far more nutrients and intense light than most aquariums can provide. For beginners, it’s best to stick with leafy greens, herbs, and houseplants for guaranteed success.

Do I still need a filter for my aquarium?

Yes, absolutely! Your plants are excellent at biological filtration (removing nitrates), but you still need a good filter for mechanical filtration to remove solid waste and debris, and to provide vital water circulation and oxygenation for your fish.

What kind of fish are best for aquaponics?

Most freshwater community fish work great! Hearty eaters like goldfish, mollies, and some cichlids are fantastic nutrient producers. Even a single Betta in a smaller tank can provide enough fertilizer for a small herb or a Pothos cutting. Just avoid fish known for eating plant roots, like some larger plecos.

Will the plants harm my fish?

Not if you choose the right ones! The plants listed in this guide are perfectly safe. The roots provide wonderful cover for shy fish and fry. The only risk is with certain houseplants (like Peace Lily or Philodendron) if a fish were to somehow get out and eat the leaves, which are toxic. The roots in the water are completely harmless.

Your Aquarium Awaits Its Green Crown

You now have a complete roadmap for turning your aquarium into a productive, beautiful, and balanced ecosystem. You know what you can grow, how to set it up, and the incredible benefits that await.

This journey is one of the most rewarding in the aquarium hobby. It connects you more deeply with the natural cycles happening in your tank and rewards you with less maintenance and a beautiful harvest.

So go ahead—grab a basil seedling or a Pothos cutting and give it a try. Start small, have fun, and watch the magic happen. Your fish, your plants, and your dinner plate will thank you for it!

Howard Parker
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