I have two mangroves in my marine tank. The taller one worries me a lot. Its top mature leaves stretch far outwards, and the new young leaf at the apex hangs down limply.

Some leaves were submerged under water before, and I only use yellow light during the day with blue night light. I also took it out many times recently, making its stem slightly soft on the surface.

Does anyone know what’s causing this drooping? How can I fix it?