Flow was switched off temporarily for the purpose of the video, this makes it easier to capture the pearling effect, otherwise the released oxygen bubbles would tend to be swirled about by the current.
Pearling usually starts a few minutes after the lights are on, mostly from the background stem plants. Blyxa Japonica also pearls but starts abit later. Even the Eleocharis sp. 'Mini' and Anubias sp. 'Petite' also pearl too, but at a much lower rate, their bubbles tend to slowly accumulate until a larger size before releasing to the surface.
I've recently received a few queries about my setup, so here are some of my latest equipment settings for reference (some have been adjusted since i started the tank in my earlier post):
Lighting: Up Aqua Z-Series Pro LED Z-20 (1 set / Old version / 180 x 0.06W LED)
Light Duration: 8 hours (10am-6pm)
Pressurized Co2: ANS Co2 System + ISTA Inline Reactor / 1bps / ~30ppm
Co2 Duration: 7 hours (9.30am-4.30pm)
Carbon Supplement: Seachem Excel / 2ml daily
Fertilizer: Tropica Plant Growth Premium Fertilizer / 1ml daily
Temperature: 29-30°C (Day) / 27-28°C (Night)
Water Change Regimen: 20% Twice Weekly