Aquariums aren’t just for fish. As an avid gardener, I wanted to learn more about how to plant potted aquarium plants.
It turns out, the art of aquascaping isn’t too far off from terrestrial gardening. You just have to understand the plant’s needs. Here’s what I learned during my research.
How to Plant Aquarium Plants in Pots
While you can easily grow underwater plants directly into the substrate, using pots has several advantages.
It offers more versatility and control while also protecting the delicate roots from hungry fish.
Planting in pots is very easy. But, there are some special precautions you must take. Here’s how you do it the right way.
Collect Your Pots
First things first, you’ll need a safe container. Whether you have fish in the aquarium or not, you need to keep the water conditions as pristine as possible. That means not adding anything that could leach chemicals.
While glazed and painted pots are beautiful, they’re no the best for aquariums. Many paints absorb water which leads to peeling. Plus, they could harbor potentially toxic chemicals.
You have two options for pot material. The first is simple plastic baskets. Made of plastic, these pots have slats that let water flow through freely.
Most aquarium plants already come in baskets. But, you can buy larger ones, too.
Add the Growth Medium
Here is where things get a bit tricky.
Do not use traditional potting soils, dirt, or loam for your aquatic plants. Aquatic plants gather their nutrients differently. Unlike terrestrial plants, they don’t rely on traditional nutrient-rich soils.
Potting mixes contain a lot of organic matter. Not only will it cloud up the water, but it will also make it dangerous for any organism. As the organic matter breaks down, it will produce a lot of ammonia and nitrates.
If you have fish in your tank, ammonia and nitrate levels need to be undetectable. Otherwise, all lifeforms in the aquarium will die.
Instead of traditional soil, use an appropriate substrate material. The substrate material is similar to what you’ll use to line the bottom of the tank. Like soil, aquatic plants use it to root and obtain nutrients.
You can use something like laterite, Rockwool, or some other commercial mix. Most mixes have safe and beneficial nutrients. Even if they’re not, the substrate should be able to hold onto nutrients from the water.
Soak the substrate material in water and pack it down into the pot. Eliminate any air bubble. Plant substrate is usually larger in size than soil, which makes avoiding compaction easier.
Prepare and Insert the Plant
Rinse the roots off to remove any stray pieces. Then, create a space for the plant in the pot and stick it in.
Surround the roots with growth medium. If the substrate is loose and fine, you can add a layer of gravel to keep it contained. Press the gravel lightly to secure the plant substrate in place.
Where to Place the Potted Plants in the Aquarium
Now comes the fun part: arranging your plants.
There are a few schools of thought here. The truth is that you can place the plants anywhere you want in the tank. As long as they have access to light, they should do just fine.
However, many aquarists like to arrange plants based on size.
When you’re looking at the tank from the front, you want to be able to see all of your plants flourishing. So, you would place the smallest plants in the foreground and the taller ones in the back.
This is the classic way of doing things.
Your smaller foreground plants will add visual interest to the underwater habitat. Meanwhile, the taller ones are great for hiding aquarium equipment.
Securing Plant Pots
Pots add a lot of weight to plants. So, they usually have no problem staying put.
But to be on the safe side, you can arrange the pots for better protection. Insert them into the gravel or sand substrate. If you need more peace of mind, you can use aquarium glue to affix it to the glass below.
Many aquarists also like to prop pots against rocks or driftwood decor for a more organic look.
Leaving Room for Animals
If you have fish or inverts, you need to consider their well-being.
Fish need ample room to swim around. Some species are active swimmers that will dart back and forth throughout the day. Others are calmer and spend their time swimming through your plants.
Whatever the case may be, it’s always good to leave some open space in the center of the tank. Arrange your pots around the perimeter of the tank. You can still enjoy the plants in all their glory while your fish can open swimming space.
What are the Requirements for Potted Aquarium Plants?
Aquatic plants grow in a completely different environment than the ones growing in your backyard. But, they still require several essentials.
Just like land-dwelling plants, aquarium plants need light for photosynthesis. It’s essential for proper growth and development.
There’s a fine balance between providing too much light and not providing enough. Without adequate light exposure, plants will quickly wilt and decay. Meanwhile, too much promotes the growth of green algae, which can quickly overtake a tank.
As a general rule of thumb, 10 to 12 hours of light every day is sufficient for most plants. Set your aquarium light on a timer.
There’s going to be a bit of trial and error involved. Different plant species will need more light than others. See what works best for your collection and stick to a schedule.
So, what kind of light works best? You can use LED, fluorescent, or high-intensity metal halide lights. They all provide sufficient lighting.
But, I recommend using LED lights above all else.
Why is that? Well, LED lights don’t generate a ton of heat. You can easily keep your tank well-lit without worrying about throwing water parameters off.
Your plants are also going to need CO2. CO2 is critical for all plants, underwater or not. They convert the CO2 into usable food compounds. It plays a critical role in photosynthesis.
In most cases, you won’t have to do a thing to add CO2. It comes naturally from fish as they respirate. CO2 also comes from the air above the tank. With proper water circulation, CO2 levels should good enough to support your potted plants.
Don’t attempt to add any additional CO2 if the levels are already fine. Excess CO2 can be toxic to fish.
How to Take Care of Aquarium Potted Plants
Once your pots are ready to go, there are still some things you need to do to keep them healthy. In the right conditions, aquatic plants can thrive with very little care.
But, a few maintenance tasks here and there can help them truly flourish.
Maintain Tank Conditions
Staying on top of tank conditions is the most important thing you need to do. Like fish, aquatic plants can experience health problems when water parameters fluctuate too much.
You must maintain pH level, temperature, and overall cleanliness.
Most aquatic plants can handle a pretty wide temperature range. If you have fish, always stick with plants that prefer the same temperature. In most cases, plants do best when the water is 75 to 88 degrees Fahrenheit.
Keep a thermometer on the glass to ensure that temperatures are always right.
The pH balance of the water is just as important as anything else. Plants will die if the water is too basic or acidic.
Again, different plant species will have varying preferences when it comes to water conditions. But, most prefer to have relatively a neutral pH balance between 6.7 and 7.8.
Finally, there’s tank cleanliness. You want to avoid any major spikes in ammonia and nitrate levels.
To keep those toxins low, perform a 30-percent water change every week. This will keep the water pristine for your plants and any other animals in the tank.
Yes, you read that right.
Aquatic plants need fertilizer, too. They require the basic building blocks for all plants. This includes nutrients like nitrogen, phosphorus, potassium, iron, and more.
Fertilizers for aquarium plants are a bit different. Instead of applying it directly to the pot, you will add a supplement to the water.
There are several fertilizers available. Choose a nutrient-rich one that’s safe for fish.
Trim and Prune
Hopefully, the underwater environment is so good that your plants thrive.
Trimming and pruning are important to the health of the plant. Overgrown plants will block light for smaller plants. Many plants get so big that they grow beyond the waterline.
Using a pair of shears, gently trim off top shoots. The more you trim, the more stunted the plant will be.
That’s not a bad thing.
It will prevent the plant from growing past an acceptable level.
How to Choose Your Aquarium Plants
The plant selection for aquariums is vast.
You can easily find plants at pet stores. But how do you choose which ones to get?
Ultimately, the most important thing is to choose plants that are compatible with any fish or inverts in the aquarium. I’ll get into more detail about that in a bit.
The goal is to create a thriving biotope where all of the organisms benefit each other.
Plants are often divided into separate categories.
Foreground plants are small and delicate. They do well in the front part of the tank.
Some plants will grow as a bush while others quickly spread to cover the substrate in vegetation.
A bit bigger than foreground plants, midground aquarium plants are quite versatile. Many get very full, filling the tank with color and life.
They work well with other decorations, too. You can place them alongside driftwood and rocks to create a unique underwater landscape.
Background plants, or stem plants, grow very long. They have a rigid stem with small leaves.
Perfect for lining the back of the tank, these plants will need regular trimming. But, they’re also very easy to propagate into a new pot.
How Long Does it Take for Aquarium Plants to Grow?
Aquariums are very controlled environments. As a result, most potted aquarium plants don’t take very long to start growing.
Generally, a new plant will take a week or two to start establishing new roots. Exact timelines will vary based on species and overall health.
Growth time also depends on how you introduce the plant. Most aquatic plants these days come as small sprouts or established plants. Thus, the hard work is already done.
That said, you do have to be careful during the first few months in the tank. Aquarium plants are very sensitive in the first 90 days. They’re adopting a new environment, so you must be extra vigilant about keeping conditions stable.
Growing From Seeds
You can try your hand at growing from seed. This process is not easy, but it’s a great way to learn how aquatic plants develop.
Just place your seeds in a pot with some high-quality growing medium. With ample exposure to light and proper water conditions, the seed should germinate in 7 to 15 days. To reach full maturity, it may take several months.
Are Potted Plants Good for Fish Tanks?
Having plants in a fish tank isn’t 100 percent necessary. But, it can do a lot to help your fish reach their full potential. Here’s how.
Plants Improve Water Quality
Potted plants don’t just enhance the look of the underwater habitat. They can improve water quality, too. Plants absorb the ammonia and carbon dioxide that your fish produce.
It’s a symbiotic relationship. The plants rely on your fish to process food. Meanwhile, the fish rely on it to soak up pollutants and provide some much-needed nutrients.
It’s a win-win.
A Natural Source of Food
Many fish species also use plants as a food source. Herbivores will sometimes eat the leaves, which could be problematic. But some will stick to just decayed plant matter that falls off.
Plants are a great source of nutrients for fish beyond standard dry flakes. Vegetation offers that extra boost of vitamins your fish needs to be vibrant and lively.
Potted Plants Offer Protection
Speaking of fish with an appetite for plants, you might encounter some species that are more destructive than others. More aggressive fish can shred plant leaves to pieces.
Even worse, they could uproot the plant entirely.
Here’s where having potted plants is beneficial. Instead of planting directly into the tank’s substrate, you can use the pot as an effective barrier from damage.
Enrichment and Safety
The goal for any aquarist is to replicate a fish’s natural environment as much as possible. While plastic decorations are cute and fun, they’re not exactly the most natural way to liven up an aquarium.
Plants, however, offer great enrichment that fish will love. It makes them feel safe.
Many fish will swim into the plant and use it as shelter whenever they feel scared.
Finally, fish utilize plants for spawning. Even if you don’t plan on breeding your fish, you could end up with several clutches of eggs.
In larger community tanks, eggs and baby fish fry are vulnerable to predators. Plants keep those babies safe and increase the survival rate.
Many fish will only spawn if there are plants nearby. They often lay their eggs on leaves.