# Pearling Requirements?



## John N. (Dec 11, 2005)

People, including me, always inject lots of CO2 and end up with lots of "pearling" - the saturation point of O2 in the water column that allows us to see bubbles coming off from plants. Like my stem of Rotala rotundifolia/Indica.










Non-pearling plants doesn't mean the plants aren't healthy and growing. However, pearling is a definately sign that things are growing well.

Question: Is CO2 required to induce pearling? Will Flourish Excel induce pearling also?

-John N.


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## Dewmazz (Sep 6, 2005)

I made a cheap diy external diffuser one day when I was bored. I blew into it a few times, thinking that It was pure CO2 I was exhaling :retard:. Any way, within 5 minutes my java ferns had large bubbles underneath thier leaves. I highly doubt that there was enough co2 content in my breath to induce such pearling, but rather an oversaturation of O2. My 2 cents.

P.S. nice photo


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## John S (Jan 18, 2005)

ok i got one if you are adding a ton co2 but your ferts arent up to par will the plants still be pearling ????


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## Riba (Feb 9, 2006)

>> Question: Is CO2 required to induce pearling? Will Flourish Excel induce pearling also?
I have a Ludwigia palustris pearling on Excel in a 32ltr tank


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## BryceM (Nov 6, 2005)

This probably isn't an easy question to answer. If you have a lot of surface turbulence, excess O2 is probably lost to the atmosphere, reducing your chance at seeing pearling. If you have a high fish load consuming O2 you'll be less likely to see it too.

Some of it probably depends on the density of plants in the tank. Even fast-growers aren't likely to saturate the water if there aren't enough of them. I've seen java fern pearl plenty of times, but I doubt a whole tank of it could saturate the water with O2 even under perfect conditions. It just doesn't metabolize fast enough.

If the pace of photosynthesis (and O2 production) exceeds the O2 loss from consumption (fish respiration, decay, etc.) and O2 lost into the air then you should see pearling. I never saw it in my tank until I did the CO2 thing though.

I'm sure that if you had a high light tank full of quickly growing stem plants with adequate nutrients and enough excel to keep the plants from being carbon limited then you could get pearling easily enough.

Like was mentioned above, plants can be doing perfectly well without pearling. Not seeing it doesn't prove something is wrong. If you do see it then you know the plants are really buzzing along. You also know it will be time to trim soon.


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