I conducted an experiment related to an earlier post made by me regarding this very issue. I had asked why plants pearl so much after a water change and not otherwise. I wanted to see what others said.
I was under the assumption that it was understood that when I said they pearl after a water change that it was UNBELIEVABLE. EVERY plant was pearling, and incredibly fast too. So I wanted to narrow down the parameters that made this possible.
One suggested it was nothing more than oxygen in the tapwater bubbling out but I ruled this out due the fact the bubbling is exactly where the pearling occurs on the leaves. The bubbling did NOT take place on the glass, like in carbonated beverages, so it must be high levels of photosynthetic activity.
I can add as much CO2 as I like. Not a factor.
I can add or subtract NO3 or PO3. Not a factor. Tapwater is not that rich in it anyway.
I can add O2. Not a factor.
I found the answer: Micro nutrients.
I have found that, with regular dosing, micronutrients (molybnium, manganese, copper, boron etc... all the TRACE elements) are the key. If one looks up a biology text on the subject, these trace elements are critically important in photosynthetic activity and rate as catalysts. These MUST be included as a part of the dosing scheme. I recommend high levels as at least if so, then if forgotten the plants will still do well.
I have to admit my plants do not pearl now as in a fresh water change, so something else must be lacking, but I will track it down. But I have proven to myself, conclusively, that the TRACE element factor is EXTREMELY important to plant pearling on a constant basis.
It only took 3 weeks of constant trial and error and observation, but it is worth it.
Aside, the high levels of nutrients I have does have some algae, be it green algae, but I dose Flourish as well, and I have NO string, hair or other algae. Only green algae, and this is to be expected with such a high nutrient level. But it is not that offensive.
Perfection is never attained, but the striving for is.
I hope this helps anyone. It may seem a no brainer, but I have found it to be a conclusive fact.
This whole post if funny. hahahaha. The reason why you see "pearling" after a water change IS because the new water is saturated with gases. This is NOT real pearling. Pearling happens when the water is saturated with O2. High fish loads, greater flow, lower lighting, lower CO2, etc make pearling more difficult. My tank pearls tons and tons. It has nothing to do with traces. I've not dosed traces weeks at a time with no end to pearling.