Why is my Cryptocoryne plant melting?
You just planted your new cryptocoryne (or crypt) plant in the aquarium, and it looks perfect for the first few days. You notice that one or two of the leaves isn’t growing well. Maybe they are turning yellow-brown, have large gaping holes, or are simply withering away. Soon, the entire plant will look as barren as a maple tree in winter. This is a common phenomenon with cryptocorynes, and it is often called “crypt melting.”
Crypts, like many aquatic plants, are sensitive to water changes. They absorb their leaves as they adapt to new conditions. The energy they gain from “consuming” the old leaves allows the crypts to create new roots and leaves that can once again gather nutrients and light in their new environment.
Why is my new Crypt plant dying?
Newly purchased plants are the most likely to experience crypt melt. Commercial farms often produce emersed-grown aquarium plants, where the leaves are in open air and only the roots are covered in water. This allows the plants to grow faster and more quickly because they can access light and carbon dioxide (CO2) from air better than from water. Growing the plants out of water also protects the leaves from algae growth, pest snails, and fish diseases.
Plant farms grow their aquatic plants with the leaves out of water to encourage faster growth and minimize algae.
If you purchase an emersed-grown Cryptocoryne, and then put it completely underwater, the crypt will transform into a submerged-grown plant that is used to absorbing light CO2 from water. The emersed leaves are usually large and broad. Submerged leaves are smaller and more delicate. Aquarium Co-Op tries to accelerate this process by providing our crypts with plenty of light and CO2 injection prior to they are sold. If your cryptocoryne starts to melt after it is planted at home, don’t throw it out. As long as it has healthy roots and is not moved once planted, you should see little shoots popping up within a few weeks. To continue growing submerged-grown leaves, ensure that the crypt is well lit and fertilized with root tab fertilizer.
What can I do about melted leaves? Cut off the leaf at the base near the substrate if you notice it is melting. Rotting leaves can lead to nitrogen spikes and algae growth. It’s best not to remove them until your cleanup crew eats the leaf.
The larger, emersed grown leaves tend to melt first and then the smaller, submerged-grown plants start sprouting.
Why Are My Established Crypts Melting?
Sometimes cryptocoryne plants may experience melting seemingly randomly, despite growing well in your fish tank for many months. As I mentioned before, crypts are highly susceptible to environmental changes like shifts in.
– Water quality – Water change frequency – Location (e.g., moving the crypt) – Lighting – Fertilizer dosing – Temperature during hot summers – CO2 injection – Fish food – Pollutants in the air
You have two options to survive the transition period: you can either trim the leaves individually as they melt or you can trim them all back to the substrate. In theory, this latter method makes the crypt focus on making new leaves instead of trying to save the old ones. Keep the aquarium environment as stable as possible, and wait for several weeks to see if the cryptocoryne plants come back. Also, remember that while the crypts are melting or pruned back, your fish tank is more prone to an algae bloom because the crypts are no longer consuming as many nutrients in the water. To help reduce algae growth and maintain a balanced tank, you might consider adding floating or fast-growing stem plants.
Do not immediately throw away a melted crypt, but rather wait at least three to four weeks to see if the plant will recover and send out new shoots.
Learn how to plant your cryptocoryne correctly by reading our article:
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