Something to note also that I've just had the realization of recently is in my tank I can control 1 maybe 2 variables that make the plants visibly pearl or not which are surface agitation and increasing the Co2 levels to match it.
While setting up my canister filter I went back and forth of what type of outflow works best and where, to cut a long story short: A spraybar that is pointed about 45 degrees up to the waterline is what I settled on.
This position has allowed me to pump a lot more Co2 into my tank faster without gassing my fish and as a result I get an insane amount of pearling, dime sized bubbles from some clumps at times.
Of course other factors such as light intensity and the water parameters that have been discussed in this thread play a big role in this also, but I could change this outflow to something else and get very little pearling with everything else the same aside from Co2 tuning for the fish, at least that was my experience.
I believe the explanation to this is because you need high o2 saturation for the plants to visibly pearl, and as an added bonus the extreme surface agitation allows a higher concentration of Co2 to be added and for it to flow around the plants meaning they have more chance to get what they need quickly.
Last edited by Quesenek; 02-09-2020 at 02:18 AM.