Got the Riccia Flauitans to pearl a while back.
What's pearling? Pearling occurs when the water becomes saturated with oxygen and no more can be absorbed. To achieve this, CO2 injection was used along with a high-quality light (LED) that produces the right light waves for plant growth. Water surface disturbance is limited to minimize the gassing off of the oxygen. Fertilizers are also added occasionally to optimize plant growth. Fish need to be monitored for CO2 poisoning.
A closer shot. Apologies for the algae in the tank. I really need to do a better job of cleaning that. Note, the Riccia was easily attached to the rock with just a few loops of tread. Hopefully overtime, the riccia will attach itself to the rock and the thread will decay natually.
Photo was taken with a Samsung S4.