Is bacopa a soft water plant or strictly very low flow?
I've tried several species over the last year plus in a high tech setup with 7.8 pH, 8 GH from the tap. Inevitably they start uprooting and eventually melt away. The latest batch of colorata has started uprooting after only a few weeks in the tank.
I use RO/DI water for my tanks and the bacopa species are doing well. It would only uproot when completely shaded for a long time. Surprisingly, when left floating it grows well on top and would even flower.