If you place one stem of a crazypearlingweed in a large tank with perfect CO2-levels and perfect nutrient levels and good light - will it pearl?

.. or do the water need to be saturated with oxygen from massive amounts of weeds?

If the water flow will be insufficient to disturb that thin layer of water surrounding leaves (Prandtl boundary) I would guess it will pearl because surrounding layer of water will become saturated with oxygen.

Regards.

Vladimir.

Ok, because the reason I ask is because I know Barr have mentioned that the pearling isn't dependent upon how O2-saturated the water is..

And if plants will pearl without O2-saturation one could use the lack of pearling even in tanks with almost no plants I guess? That would make it easier for folks with non-planted tanks that use CO2+PMDD to see if they need to dose more PMDD.

How is possible to see pearling without the water column being saturated with O2 since they will always be ready to take it if under-saturated? Plants add pure O2 to the water column via H2O splitting and the only way you can see plants do that is when the water column is satured with O2. (The process of O2 addition from plants via H2O splitting is continuous but can only be visible once the water column is satured.)

Regards
Peter Gwee

Vladimirs theory sounds valid..

The answer is yes if the growth rate is fast enough.

If the plant produces enough O2 and expels the gas through growth(plant production), then you will see it.

O2 is rather insoluble, and is not easily lost around the layer to the water, so we can see pearlign at less than saturating O2 ppm's also.
I've seen a lot of pearling in tanks and lakes with lower O2 ppm's.

Regards,
Tom Barr