VaughnH;30804 said:Oxygen is only slightly soluble in water, so if a plant produces oxygen faster than it can be dissolved into water, a "pearl" of oxygen results.
helgymatt;30836 said:When does it occur?
In my experience pearling will be highest when CO2 is optimum. I have high light and good ferts so those also play an important role.
When my CO2 is good I have amazing pearling, when CO2 is not optimum, like when a tank runs out or when the concentation is just not high enought, I get little to no pearling.
Remember that just because a drop checker is green, that doesn't mean that you have enought CO2. It is just an indicator. My drop checker is usually yellow-green when CO2 is highest at days end.
Try to bump up your CO2 slightly and see what happens. Keep a very close eye on the fish! My pH in my tank goes from 7.2 to about 6.3 after the CO2 has been on for a while.
aquabillpers;30808 said:Is their a relationship between the amount of O2 already in the water and "pearling"?
It used to be said that pearling would only occur when the water contained all of the O2 that it could hold, but I think that is no longer considered accurate.
Chiya;30892 said:Hi all,
Just curious, we know photosynthesis causes pearling. BUT, is it a good sign of healthy plant growth?
My plants do produce little O2 bubbles, which float upwards and dissolve almost immediately.
I've not seen pearling in my tanks for as long as I had them.
There was a thread regarding pearling.
There was mention that pearling happens when plants are overworked.
Hence it makes sense if pearling happens when there's a saturation of O2 in the water.
Plants are overworked, producing more O2 than normal.
O2 production > degas rate + respiration
O2 reaches a saturation level in the water. O2 is unable to dissolve into the water fast enough.