a string of bubbles usually come from an injured part of the plant (like when you do a trim). this is accelerated by high light
That sounds more like it. Because every pearling pic I've seen in the o2 just sitting on the plant. I can see it from the stems as I trim them about every 2 weeks, but from my crypts? I haven't touched those for months. They are doing so good as almost every crypt I have has sent off multiple runners.