How To Add Live Plants to an Established Aquarium In 7 Easy Steps

Many people have aquariums because they love the calming effects of watching pet fish swim around. Adding plants can seem like it detracts from the fish and crowds your tank. However, the opposite is true—plants keep water clear, filter out organic waste, and prevent algae from growing on the glass.

If you’ve had an aquarium with only fish, you might not know where to start with adding plants. There’s no need to empty your current tank and build from scratch. You can learn how to add live plants to an established aquarium in 7 easy steps.

How To Add Live Plants to an Established Aquarium In 7 Steps

Many people think they can only add plants to a new aquarium. While starting fresh and adding plants directly into the substrate can be easier, you don’t need to go that far. The following seven steps show you how to add live plants to an established aquarium and keep them healthy. Be sure to read our post on cleaning a planted aquarium once you’re done!

1. Pick the Right Plants

The right plants will grow well in water, but there will be constraints regarding the temperature, substrate requirements, and light needs. For example, some plants need a thicker layer of substrate—up to three inches—for the roots to mature. Others might need up to eight hours of light to grow, whether from the sun or your aquarium lighting.

There are many aquarium plants, such as pothos, to choose from, so you can decide according to your tank’s aesthetic and how much maintenance you want to handle.

If you’re looking for lush floor coverage, you can choose from plants like Hairgrass, Dwarf Hairgrass, or Vallisneria. Hairgrass and Vallisneria look like grass you’d see on your lawn, with bright green blades. Dwarf Hairgrass is short and vibrant and looks like a thick carpet along the bottom of your aquarium.

Leafy plants, such as Amazon Swords, add a lot of greenery to your tank. The low-maintenance plant doesn’t need a specific water temperature to grow long, slender leaves.

Java Fern has larger leaves that your fish will swim through and hide beneath. Anubias is a low-growing leafy plant that doesn’t require much sun.

Fancier plants require some set standards regarding water temperature and light, but the beauty they add to your tank is well worth the effort. Madagascar Lace has delicate leaves that resemble a lace pattern. Plants need a lot of light and fertilization.

Red Tiger Lotus plants have large leaves with a red tint. It flourishes, so you have to trim it regularly.

You can also choose plants based on the overall look of your aquarium. If you have a tropical tank, add Waterweeds. The meandering stems have countless leaves all over, resembling seaweed. Hornwort gives a similar ocean vibe to your tank.

If you decorate your tank with sand and shells to resemble a beach, you might want to grow cryptocoryne plants. These slow-growing plants look like something you’d see at the beach. They come in green, olive, brown, and red-tinted shades. They grow to look very different depending on the aquarium conditions.

2. Grow Some Plants

You can grow your plants while you learn how to add live plants to an established aquarium. Since it’s usually easier to add plants with mature root systems, you can start seedlings outside of the aquarium.

Nurture aquatic plants just as you would a house plant. If you’re starting from seeds, first soak them in clean water to help soften the exterior.

Fill a pot with moist moss and soil and plant the seed. Keep it in that pot until the stem breaks out and begins to develop roots. You’ll want to check the soil often to keep it wet since these plants will eventually live in water.

The process may take a week or two, depending on the plant type. Once it’s two or three inches tall, it’s strong enough to live in the aquarium.

Handle them gently as you remove them from the pot and plant them in your tank substrate. You might even choose to put them in the aquarium in the pot since that prevents them from floating in the water.

Introducing plants with established root systems makes it more likely for the plants to grow strong and healthy. It also makes them more likely to flourish if your fish come to explore them a little too excitedly.

3. Clean the Tank

Before introducing plants to your aquarium, clean the tank. You want to eliminate any fish waste or harmful buildup from the water and walls. Move the fish to a temporary environment while you use the gravel vacuum on your substrate.

Check the water to ensure you have balanced pH levels. You might need to remove some water to add the plants without the tank overflowing. 

4. Properly Place the Plants

You want to place plants where your fish can enjoy them, especially the leafy plants that provide fun hiding places. But you don’t want to overcrowd any area of the tank.

You also don’t want to add so many plants that your fish don’t have much remaining open water. Plant them at least half an inch apart so they won’t fight for space and resources to grow.

How you’ll plant your greenery depends on the substrate you use. For example, you can directly place some plants in an inch or two of sand. If you use gravel, you want to clear a small area, put in the plant, and loosely cover the roots with pebbles.

Take care not to put them directly on the roots, where they could damage the plant or prevent it from flourishing.

how to add live plants to an established aquarium

You can also use various weights to keep plants in place. Buy plant anchors or suction cups at fish supply stores for a quick fix.

You can get innovative with your weights to help them fit in with your tank’s aesthetic. Use a fishing line to loosely tie a plant to a piece of driftwood, or plant them in deep crevices of your decorative rocks.

5. Fill With Water

Once your plants are in their new home, you can add extra water to your tank. Fill it as full as you normally keep it for your fish. Make sure you’re paying attention to the water temperature, especially if you just planted high-maintenance greenery that thrives in specific types of water.

You’ll want to add fertilizer for the plants according to the package’s instructions. Most fertilizers require one cap per 40 gallons of water.

6. Re-introduce the Fish

Carefully re-introducing the fish is a major step to follow as you learn how to add live plants to an established aquarium.

When you add fish to a new aquarium, you put their bag in the tank to let them adjust to the temperature. After ten minutes, you add a cup of the tank water to their bag. Once they acclimate, you add more tank water to their bag.

Since the plants are a new addition to your fish’s environment, you want to take these same precautions. You’ve introduced foreign life, as well as fertilizer your fish haven’t experienced before. Let the plants stay in the tank for a day or two before re-introducing your fish to the environment. We’ve explained how to quarantine aquatic plants here.

Watch your fish and see how they explore and enjoy the new plants. It may take them some time to appreciate the greenery, but they’ll love the plants’ benefits just as much as you.

7. Maintain the Plants

It’s not enough to know how to add live plants to an established aquarium—you need to care for them once they’re in the water so they don’t die. There are new layers of maintenance for live plants compared to a fish-only tank or a tank that has plastic plants as decoration.

Plants that live in the soil get nutrients from the ground. Your aquatic plants will get some nutrients from the fish waste, but they’ll also need fertilizer.

Depending on how many plants you have in your tank, you might need to fertilize two or three times a week. Check specific care instructions for your plants, or follow the instructions on your plant fertilizer.

Aquatic plants need varying amounts of light. Some might only need a few hours a day, while some need up to eight hours to grow properly. You can provide light by keeping your aquarium near windows to provide natural sunlight. If you use a light for your fish, this can benefit your plants, too.

You might need to trim your plants as they grow. Some don’t spread much, but Red Tiger Lotus and some grasses will try to overtake the tank.

It’s better to start with a plant or two as you learn how to add live plants to an established aquarium. You’ll learn how to care for them and see how they grow, so they don’t harm anything else living in your tank.

Plants help keep the water clear, so you’ll love that feature, along with how the plants elevate the look of your tank. Though you might need to add some steps to your maintenance routine, plants keep the water cleaner, so your fish will benefit.


Live plants are a welcome addition to any fish tank, not just aesthetically, but also as natural filters. By following the steps outlined above you can easily learn how to add live plants to an established aquarium in 7 steps.

Keep up with the latest aquarium tips and insights!
Follow us on Pinterest:

Similar Posts