Help with tiger lotus?

[Runsoncoffee]

I kill every one of my tiger lotuses. I do root tabs, flourish, and iron supplements. My aquarium has a very bright light as well. But any lotus I buy just slowly melts into nothing. Most of the bulbs break off before I can get them in the substrate, and from there the plants just kinda dye.
Any advice would be appreciated for how to not kill this plant, and how to have the bulb not break off
Thanks