Emersed vs Submersed Grown Aquarium Plants: Why Does it Matter?
Whether you are new to the aquarium hobby or have been doing it for years, there is a good chance you don’t know the difference between emersed and submersed grown aquarium plants. In simple terms, emersed grown plants are grown out of water and submersed grown plants are grown underwater. However, it is worth noting that hobbyists will refer to these states of growth in different ways, which can be confusing. To clear things up, see below:
Emersed Grown (Above Water)
Submersed Grown (Below Water)
How do I know what I am receiving?
Some aquarium plants will look drastically different in their emersed form whereas others will look quite similar. Take for example the two images below. The first image (from left to right) shows Ludwigia Arcuata, Ludwigia Palustris and Bacopa Monnieri grown in their emersed form whereas the second image shows them in their submersed form. The bacopa looks quite similar in both photos but the two Ludwigia species look quite different.
Nonetheless there are still other ways to make an educated guess as to what you are buying.
If you are making a purchase online, a good seller will specify the form of their aquarium plants. However, in Australian pet/aquarium shops, you will typically see aquarium plants sold in two different ways. Either in tanks and under the water or in small round plastic containers.
Believe it or not, the plants in the tanks are not necessarily submersed grown. They are often purchased from a wholesaler in an emersed form and have been placed in tanks for sale purpose. Therefore they are likely to be in their emersed form but transitioning to submersed form. Sometimes these plants are submersed grown, but asking an employee of the store will be your best bet.
The plants sold in the small round tubs are called tissue culture plants. These plants are grown in sterile conditions and are guaranteed to be free from pests and algae. They are great for planting smaller aquariums, but can be expensive when bought in larger quantities. These plants are emersed grown.
Why Does it Matter?
Knowing what state your aquarium plants are grown in is important for three key reasons:
When purchasing plants that are grown in a submersed state, they can potentially carry pests such as snails, snail eggs, hydra and planaria. Snails are unsightly in large numbers but can help to clean algae and decaying matter. Planaria and Hydra, however, can be lethal to shrimps. Even if these plants have been sent in the mail, these pests will likely survive the journey and could thrive in your aquarium. If this is something that bothers you, we would recommend purchasing emersed grown plants as they are free from these pests.
Submersed grown plants are also more susceptible to algae. All aquariums have some form of algae, so plants that you receive in a submersed form will likely carry some form of it. As long as your aquarium is well balanced, this should not be an issue. Given that there are some algae eating fish or shrimp in your tank, it should soon disappear. However, if you receive a submersed grown aquarium plant with an immense amount of algae, this can throw off the balance of your aquarium. The newly introduced algae may outcompete your current plants for lights and nutrients and begin take over the tank. In saying this, we suggest taking extra caution when buying from a source that may be unreliable.
So why not just buy emersed grown plants? They are free from algae and snails and generally they will ship better too. Well, the issue with emersed grown aquarium plants is that they have to transition back to their submersed state once placed in your aquarium. Depending on the plant species, this process can go just about unnoticed or leave you stressing about the money wasted on your new plants.
If you are not injecting Co2 into your aquarium this could be an issue. The transition from emersed to submersed is generally easier with adequate Co2. Nonetheless, it can still be done. With balanced lighting and nutrients and enough patience, your plants will reach their fully submersed form and begin growing as you would expect.
All considered, the best plant purchase for you will depend on your personal preferences and aquarium setup. A ‘high tech’, balanced aquarium with Co2 injection will generally make the transitioning process a breeze. The only drawback being that it will take a little bit longer for your plants to ‘take-off’ and fill in your aquarium. If you’re running a basic aquarium setup and are unsure if you have the patience for plant conversion, then submersed grown may be right for you. Keep in mind that each plant will react to different conditions in different ways. Sometimes your own experimentation is the best way to find what is right for you 😊.