Why is my Cryptocoryne Pot Melting?

Why is My Cryptocoryne Pot 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. 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 phenomenon is very common with cryptocorynes and is often called “crypt melt.”

Crypts (and many other live aquatic plants) are very sensitive to major changes in their water, so they respond by absorbing their existing leaves as they adjust to the different conditions. They “eat” the old leaves, which gives them energy to make new roots and create new leaves that can absorb nutrients and light.

Why is my new Crypt plant dying?

Newly purchased plants are the most likely to experience crypt melt. Emersed-grown aquariums are commonly grown on commercial farms. This means that the leaves and roots are left in open air, while only the roots are watered. 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.

Aquatic farms grow aquatic plants without water in order to promote faster growth and minimize algae.

An emersed-grown cryptocoryne must be fully submerged before it can become a submerged-grown plant. All the thick, broad, emersed leaves usually melt away, and smaller, thinner, submersed leaves appear in their stead. 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. 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 should I do about the melted leaves? If you see a leaf is clearly melting, cut it off at the base of the stem near the substrate. Rotting leaves can sometimes cause nitrogen spikes or algae growth, so it’s best to remove them unless your clean-up crew members consume the dead leaf first.

Larger, emersed-grown leaf usually melts first, then smaller, submerged-grown leaves start sprouting from the substrate.

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 mentioned previously, crypts are very susceptible to environmental changes, such as 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. The theory is that this will allow the crypts to focus on making new leaves, rather than trying to save existing ones. You should keep the aquarium environment as stable and allow the plants to grow back for several weeks. 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:


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