Cryptocorynes grow best in low light tanks. Too much light encourages algae to grow on the slow-growing leaves. They grow slowly but steadily. Crypts do not like being moved.  Transplanting them stops their growth for a while. Potted crypts usually take the move to another tank much better

Enemies. Avoid plant eaters such as hatchetfish, silver dollars and most large plecos. Frequent small amounts of fertilizer work better than occasional big dosings.

Requirements. Cryptocorynes (and most rooted plants) root best in a smaller substrate about the size of a BB. Their roots and rhizomes grow right below the surface and spread widely. Gravel vacuum cleaners will disturb them.

Reproduction. Not many people will go to the effort to harvest crypt seeds. You need to gradually lower the water level until the tiny blooms appear and get fertilized. Nearly everyone grows new crypts through their rhizomes.

Crypt Wilt. Crypts do not like floating in a tank unplanted. And sometimes just moving them to another tank with different lighting and water conditions will make their leaves wither and disintegrate.  Plant the root base and be patient. Over time, crypts usually re-grow.