Pearling

C

csmith

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Can pearling be used as a very rough measure of Co2 saturation? By this I mean if everything is pearling within an aquarium, can that be used as a somewhat certain measure of non-limiting Co2, atleast on a small scale, e.g. 10 gallons? If within the space there isn't an area without bubbles and all flora pearl what're the chances sufficient saturation is occuring?
 

Philosophos

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Pearling is a great confirmation of non-limiting CO2 saturation. If your plants are pearling heavily all day long on a regular basis, then you're doing well.

At the same time though you need enough light to make them pearl, which isn't necessary for healthy growth. Turbulent flow can also knock bubbles off in some situations easier than others.

So, in short, you can have very excessive CO2 saturation without pearling. If you have pearling, the areas that are pearling are definitely not lacking in CO2. IME the light required for pearling everywhere also means you're really working hard at your CO2 and trimming so often that a weed eater sounds like a healthy investment after a while.
 
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csmith

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That was the answer I was hoping for. I really wanted to avoid putting a drop checker into my tank, there's enough hardware as is. I can't confirm they're pearling all day long (as I'm at work when the lights come on), but they definately are when I get home.

Trimming won't be a problem, these suckers are going to grow up and out. Thanks again.
 

Philosophos

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No problem.

A drop checker doesn't have to be a permanent feature of the tank either though. I often use one to start a tank, to troubleshoot, or after changing up flow in a big way, then pull it out and move it to the next tank.

I've also found drop checkers get people interested in planted tanks. Every time someone unfamiliar with planted tanks comes over and takes a look, they ask what it is every single time without fail and the explanation almost always intrigues them.
 

jonny_ftm

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I don't agree that much light is needed for pearling. I'll take a photo tomorrow of my tank pearling like crazy under 0.9wpg light: moss, riccia, glosso and even anubia. Moss is magic when covered with bubbles. Hope though that my camera can get a nice shot of this.
 

Biollante

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csmith;48644 said:
Can pearling be used as a very rough measure of Co2 saturation? By this I mean if everything is pearling within an aquarium, can that be used as a somewhat certain measure of non-limiting Co2, atleast on a small scale, e.g. 10 gallons? If within the space there isn't an area without bubbles and all flora pearl what're the chances sufficient saturation is occuring?

Hi,

No, pearling only indicates that you have achieved Oxygen saturation with photosynthesis taking place. :gw

CO2 saturation at 77 F (25C), 100 kPa is 1.45 g/l you only want 30-40-ppm CO2 where Oxygen saturation is about 8.3-ppm. In other words CO2 is far more soluble in water than O2

Technically pearling only proves Oxygen saturation with photosynthesis taking place.

For our purposes though, pearling is a good indicator of CO2 and happy plants. :D

Biollante