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. Then you notice that one or two leaves aren’t doing so well. They might be turning yellow-brown or have large, gaping holes or simply withering away. Soon, the whole plant appears as naked as a maple leaf in winter. This is a common phenomenon with cryptocorynes, and it is often called “crypt melting.”

Crypts and many other aquatic plants are extremely sensitive to changes in water quality. As such, they absorb the existing leaves to adjust to changing 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?

Most often, crypt melt occurs in plants that have just been purchased. Emersed-grown aquarium plants are often grown in commercial farms. The leaves are exposed to the air while the roots are kept 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 helps to speed up this process by giving our crypts lots of light and CO2 infusion before they are sold. However, if you see your cryptocoryne melting after you plant it at home, do not throw it away in the trash. You should start to see tiny shoots within weeks, as long as the roots are healthy and it isn’t moved after being planted. If you notice new growth, ensure the crypt has sufficient lighting and root tab fertilizer so that it can continue to grow submerged-grown foliage.

What to do with melted leaves. 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 we have mentioned, crypts can be affected by environmental changes such as shifts in the environment.

– 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 can either cut the leaves as they melt one at a time or trim the entire tree back to its substrate in order to survive the transition. This allows the crypt to concentrate on creating new leaves and not trying to save old ones. The aquarium environment should be kept as stable as possible. Wait several weeks for the cryptocoryne plant to return. 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. Consider adding some fast-growing stem plants and floating plants to help minimize algae growth and keep the tank balanced in the interim.

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:

Subscribe

Recent blog posts

– Top 5 Easy Fish Breeding Ideas for Your Next 20-Gallon Aquarium – How to Balance Aquarium Lighting to Grow Healthy Plants (and Avoid Algae) – Care Guide for Rummy-Nose Tetras – Aquatic Canary in the Coal Mine – Colony Breeding: The Easiest Way to Breed Livebearers for Profit – Top 10 Amazing Rainbowfish for Your Next Freshwater Aquarium