How To Plant Aquarium Grass Seeds? – The Complete Guide!

An aquarium having a green carpet looks ethereal. But it’s not easy to achieve that. Especially as a beginner, you might have the urge to throw dry seeds into an aquarium full of water. But anybody can tell it’s not the right way. So, here’s your guide on how to plant aquarium grass seeds.

Empty the aquarium and make a seed bed for the grass seeds. Evenly spread the seeds on the bed and spray some fertilizers. Finally, cover the whole tank with plastic wrap to ensure humidity and moisture. The seeds will start sprouting within 3-4 days.

Growing the seeds from scratch enables you to customize the whole process and save some money. So, keep following the article if you want a detailed insight into this topic.

How To Plant Aquarium Grass Seeds? A Step-By-Step Guide

Think about an egg first. Can it hatch on its own? No, obviously. You have to fulfill the temperature requirement and many other requirements.

It’s the same with growing grass seeds as well. You can’t just throw the seeds into your tank and expect to see grass growing. There’s an intensive step-by-step formula for that. And we are here to describe that to you. Have a look.

1. Pick The Grass-Type

The very first step would be choosing the right grass seeds. You might want a grass that covers the aquarium floor like a carpet. Dwarf hair grass, four-leaf clover, and baby tears are some of your best options.

In another case, you might like small patches of aquatic plants that resemble grass like Java moss. The plantation method depends on the species. It’s better to grow some plants with a dry start.

On the other hand, some aquatic plants don’t have the structure to hold themselves up without water. So, you have to grow aqua plants like Najas and Blyxa while submerged underwater.

2. Select A Plantation Method

Once you know how you want the aquarium to look, it’s time to consider the plantation method. Do you want a dry-start? If you are new to this word, dry-starting means growing roots outside the water.

When the seeds sprout, gently add water to the dry tank. It’s more suitable when you aim to cover the entire aquarium bottom with grass. It would be difficult to submerge patches of soil and grass when the tank is full of water. The soil chunk might break and cause the plants to float inside the tank.

We think dry-starting is the right way to avoid such accidents. However, if you are thinking about adding small patches of dwarf plants across the tank, follow the next section of this article.

3. Prepare The Seedbed

You will need an empty tank for that. If you don’t have a new tank, use the existing one. Transfer the fish to a new bowl for some days. Then, remove the water as well as all the other decorations like stones and plants.

Now, grab a bag of gravel to cover the aquarium’s bottom. Spread it out evenly and try to create a thick layer.

Prepare The Seedbed

Remember, finer gravels are easier for grass seeds to root down. You can use a bag of Fluorite for the base. It is a natural substrate that ensures the greens are getting enough nutrients. For a 20-gallon tank, you wouldn’t need more than one packet.

If you don’t have enough gravel for a thick layer, that’s okay too. You can increase the thickness with an extra layer of eco-complete substrates that enhance the growth of a planted aquarium.

4. Cover The Bed With Seeds

The seedbed is ready. It’s time to spread the grass seeds. Grab the packet of seeds you bought from the store earlier. Take the seeds out and keep them moist. You can put them inside a water bowl for 2-3 days. It’s highly advisable not to open the packet unless your seed bed is ready to use.

Now, spread the seeds across the bed evenly. Once the bed is covered, spray some fertilizer on it. Here’s how to do that. Fill a one-ounce bottle with water and mix ¼ ounces of liquid fertilizer. Increase the bottle size depending on your tank’s requirement. But make sure to maintain the same ratio of water and fertilizer.

You can use any liquid fertilizer you want. In case you want a suggestion, “Flourish” from Seachem works fine.

Finally, spray the solution on the seedbed and make it moist. After that, put an additional substrate layer on top of the bed. It should be a thin one. The purpose is to let the outer layer soak any excess moisture within the bed.

5. Let The Seeds Germinate

At this stage, all you have to do is wrap up the whole tank. You can use plastic sheets and cover the top of your aquarium. This simple step traps moisture inside the tank. The much-needed humidity helps the seeds to grow faster.

Now, all you can do is wait. Open the plastic wrap for 20-30 minutes a day for new air intake. After that, wrap up the tank again. Also, ensure 10-12 hours of lighting per day. Lighting initiates the photosynthesis process. So your grass will grow at a faster rate.

Let The Seeds Germinate

It might take 14 to 17 days for the soil to form a green carpet. You will start seeing sprinkles of greenery on the 3rd day itself.

how to plant aquarium grass seeds step by step guide

Note: Don’t put the tank beside a window for too long. The seeds can get cooked under due to the hot sun.

6. Add Water Into The Tank

You are almost done. Your aquatic carpet is ready. All you have to do is relocate the fish and other decorative objects like stones inside the tank. Remember to be as gentle as possible while pouring water. You don’t want to damage the newly grown grass. The best way is to grab a mug and slowly pour water from the corner.

Then, insert the small fish bowl into the tank and let them swim out. It’s a far better way than catching the fish with a net. Your aqua pets might get traumatized if you do that frequently. It’s important for fish to feel comfortable and safe during the relocation.

Next, add the plants and other objects one by one. There you go! Your fish tank has a beautiful green carpet.

Can I Grow Aquarium Grass Seeds Outside The Tank?

Aquarium owners sometimes want patches of grass instead of a full carpet. For that, you can follow the same Dry-Start method mentioned above. But when it comes to spreading the seeds on the bed, don’t cover the whole area. Just sprinkle the seeds where you want traces of greenery. And you would be good to go.

That being said, some species of aquatic plants have trouble sprouting underwater. You must submerge them into the tank after the germination process. So, here’s the guide you have to follow while growing aquarium seeds outside the tank.

Step-1: Prepare Multiple Seed-beds

Grab a plastic container or ceramic bowl. If you want several batches, prepare more seedbeds. Put some aquarium substrate in the bowl. Then, rinse the bowl along with the substrates. Drain the water as much as you can. The purpose is to avoid a dry seedbed.

Step-2: Sow The Seeds

Place the seeds in the bowl using a spoon. Make sure the seeds are laying on top of the substrates. Don’t cover them with soil yet.

Sow The Seeds to Grow Aquarium Grass Seeds Outside The Tank

Next, give two-three spirits of liquid fertilizer into the bowl. Use the same method and ratio we described earlier. Once the bed is soaked, put some dry gravel in the bowl. This new layer will cover up the seeds.

Step 3: Let The Seeds Germinate

Finally, wrap the bowls with plastic sheets properly. The germination process is pretty much the same as before. Let it be under direct artificial lighting for 10 hours a day. After that, shift it inside a box.

Let The Seeds Germinate to Grow Aquarium Grass Seeds Outside The Tank

Step 4: Relocate

Once the germination is done, you are left with small bowls filled with small grass. It’s time to relocate. For that, remove the grass from the ceramic pot. Just flip the bowl over.

Relocate to Grow Aquarium Grass Seeds Outside The Tank

Since the gravels are pre-washed, you can directly put them inside the aquarium. Dig the aquarium floor a little. Place the grass patches on the gravel and secure it properly. The relocation process is a bit different than the previous method.

Things That Affect The Growth Of Aquarium Grass Seeds

Certain things affect the grass seeds while they are growing. If you ever tried to germinate the seeds before and failed, these factors must have had something to do with that. So, check them out before taking up the project.

1. Carbon Dioxide (CO2)

Any plant will thrive if there is a consistent distribution of CO2. Your aquarium grass is no different. to ensure positive growth, buy a diffuser from the pet store. Insert it into the tank water.

The diffuser collects CO2 from the air and transfers it into the tank through bubbles. As a result, the water easily absorbs the CO2 and carries it to the grass at the bottom.

2. Temperature

The ideal temperature for germinating seeds is around 70 to 77 degrees Fahrenheit. However, before buying the seeds, you should always ask the seller for the ideal temperature.

Also, avoid keeping the seedbed outside when the sun is too bright or it’s snowing. The moisture locked inside might evaporate, leading to dryer soil. Or the low temperature will cause the seeds to freeze. You don’t want that to happen.

3. High-Quality Fertilizer

During the initial stage, it’s highly advisable to spray fertilizer on the soil. It provides essential nutrients in the soil. If you are a beginner, just buy any SeaChem nutrient solution. It’s a safe option.

Once the grass becomes stronger, less fertilizer will be required. Fully grown grass uses food waste and fish poop as a source of nutrients and thrives.

4. Artificial Lighting

We have already discussed why keeping the seeds outside is a bad idea. Even if the sun is not bright, the temperature might not be suitable for growing seeds.

Hence, expert aquarists suggest using artificial LED lighting as the main source. Install the lighting on top of the seedbed and lit it up for 12 hours straight. Since you are using the artificial method, you can also turn the lights on during the night.

However, controlling light exposure during the day would be easier as you stay awake.

Is Growing Aquarium Grass Seeds Really Worth It?

It’s not impossible to be overwhelmed by the entire process. You might be questioning whether it’s worth the effort or not. Let’s clear that out.

Is Growing Aquarium Grass Seeds Really Worth It

Having a grass floor in the aquarium helps the fish in numerous ways. First, the introvert species roaming around the tank will love this new element. They have a new place for hiding and resting.

Apart from that, grass ensures the tank has enough oxygen in circulation all the time. It’s always better to boost the oxygen level. Here you can do that without adding an extra machine.

Besides, the growing seeds will consume pollutants like fish waste and leftover food. These ingredients make great natural fertilizers. You have to worry less about cleaning up these micro-particles.

As you can see, it’s a win-win situation. Growing the seeds from scratch is even better than store-bought grass carpets. It gives you a sense of satisfaction and saves a ton of money.


We are almost at the bottom of our guide. You must have already got most of your answers. In case we missed anything, check out this FAQ section below. It might clarify the doubts you have about growing grass seeds.

How Do I Keep My Aquarium Grass Alive?

The process of keeping your aqua-grass alive is pretty much similar to any other type of vegetation. You have to ensure 10-12 hours of exposure to artificial lighting per day. High-quality fertilizer and nutrients help the grass to grow faster. Also, avoid adding fish that like to dig the aquarium floor a lot.

Which pH Level Is Suitable For Growing Aquarium Grass?

Always ensure the tank’s pH level is within the 7 to 7.5 range. If it goes below 6, then the water becomes too acidic and causes an interruption in the nitrogen cycle. On the other hand, if it goes above 8, then the water contains a high percentage of toxic ammonia.

What Level Of Ammonia Is Good For Aquarium Grass?

Aquatic plants and grass aren’t vulnerable to ammonia like fish. The nitrogen within the ammonia even helps the grass to grow. But too much ammonia is always a red flag. Try to keep the ammonia level lower than 2 mg/L.

What Kind Of Soil Is Best For Growing Grass Seeds In A Fish Tank?

Clay-based soil makes the most suitable bed for grass seeds. The size of granules should also be considered while buying. Large granules work best for plants with stronger roots. On the other hand, finer granules are the most suitable for grass. It is easy to root down.

Wrapping Up

Growing the seeds from scratch is always harder. But imagine the amount of money you can save. Pet stores sell soil chunks with aquatic grass and plants for as much as $10 to $20. That’s almost $50 to cover the whole aquarium floor.

Instead, you can follow our guide on how to plant aquarium grass seeds. You don’t need any sophisticated equipment for that. We believe you already own gravel, fertilizers, LED lighting sources, etc. Go to the nearest pet store and get a packet of grass seeds only.

You see, growing a grass carpet for your aquarium is not only for visual appeal. It has many bio benefits and helps the tank’s inhabitants feel more comfortable. We would highly suggest you follow the guide and try growing seeds yourself.



About The Author

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top