Can Pearling Occur with a Nutrient Deficiency?

Ratfish

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Sep 16, 2009
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It seems like photosynthesis itself doesn't require all of the nutrients that we use to fertilize, but obviously the plants need it, so would an unhealthy plant still visibly pearl? I just tore down and replanted most of my little 10 gallon tank, but it's still like a champagne glass, so I'm wondering if that can occur if the plants are deficient in some nutrient or if that is a safe metric for healthy plants in general.

Any thoughts are appreciated.
 

Philosophos

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You can get pearling with column deficiency, but I've never seen a plant pearl once deficiency is a visible issue. The bubbles everywhere may be due to the fact that you just refilled the tank, and the O2 saturation is very high. Got bubbles on the glass by chance?

-Philosophos
 

nipat

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May 23, 2009
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My ugly Stargrass pearled heavily even when they were melting.
Might be from cracks and wounds.
 

Biollante

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Oxygen Saturation

Ratfish;40874 said:
It seems like photosynthesis itself doesn't require all of the nutrients that we use to fertilize, but obviously the plants need it, so would an unhealthy plant still visibly pearl? I just tore down and replanted most of my little 10 gallon tank, but it's still like a champagne glass, so I'm wondering if that can occur if the plants are deficient in some nutrient or if that is a safe metric for healthy plants in general.

Any thoughts are appreciated.

Pearling per say is only an indication of oxygen saturation. We tend to over use pearling as an indication of overall health, but in and of itself it means little.

As Philosophos says it may simply be that you mixed a lot of oxygen in during the change.

Biollante
 

Ratfish

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Sep 16, 2009
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Oh no, this is days after the last water change and it starts when the lights have been on for about 30-45 mins and is definitely coming from all of the plant leaves.
 

Ratfish

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Sep 16, 2009
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Well, my plan was to not fertilize until pearling stopped, but that was assuming that pearling would be prevented by a deficiency. The tank has plenty of snail/shrimp/fish waste to at least provide nitrates, I'm assuming.
 

Biollante

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Liebig's Law of the Minimum

Just as plants from a store arrive they can easily go for 10-12 days on their reserves, people sometimes fool themselves into thinking all is right with their tank when it really is simply the plants had to be well taken care of before they got them.

The problem with letting them go is that as in the above example, what you are doing is using up their reserves and will stress them and though they may come back, they are less resistant to disease and other stresses.

Liebig's Law of the Minimum is the predicate for EI. We do not want ever to limit anything needed for growth. This is a cute illustration Law of the Minimum - Liebig's Law.

If they are pearling (and it is not algae covering the plants pearling), the plants (or algae) are producing oxygen as a product of photosynthesis, that requires nutrients from somewhere. (Technically, Co2 fixation can occur in the dark if RuBP is present.)

Biollante
 

mr_convitbau

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Feb 13, 2009
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Most of us think that pearling only occurs when water is saturated with oxygen. Pearling, however, occurs when the rate of O2 producing exceeds the rate of O2 dissolving in water. For instance, let's say if plants produce 10 oxygen bubbles per minute, but only 8 of them can dissolve in water during that one minute period of time, then 2 remaining bubbles will appear under the leaves, and we will see pearling.

We can have a tank with less than 100% O2 saturation, and we still see pearling, according to Tom.

Regards,
TL
 

Biollante

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If Tom Said It...

mr_convitbau;40896 said:
Most of us think that pearling only occurs when water is saturated with oxygen. Pearling, however, occurs when the rate of O2 producing exceeds the rate of O2 dissolving in water. For instance, let's say if plants produce 10 oxygen bubbles per minute, but only 8 of them can dissolve in water during that one minute period of time, then 2 remaining bubbles will appear under the leaves, and we will see pearling.

We can have a tank with less than 100% O2 saturation, and we still see pearling, according to Tom.

Regards,
TL

I am not familiar with that definition of pearling. That sounds more like undissolved CO2 trapped under a leaf.

Under that definition I could have pearling by running aerating stones or that tubing with lots of holes nuder the plants and trap the air or whatever gases under the plant leaves.

Or are you suggesting the CO2 was sucked into the leaf and expelled in another location?

If Tom (assuming you mean Tom Barr, The Administrator) said it, it must be so.:eek:

Biollante
 

mr_convitbau

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Feb 13, 2009
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Hi,

I am not an expert in this field, meaning I do not know what the limit and how fast gaseous CO2 can dissolve in water.

Let's just make it this way. When we use the disk diffuser, why do we still see CO2 mist or bubbles coming out of the disk even at the very first time the CO2 valve is opened. I do not believe, at this stage, that tank water is 100% saturated with CO2. We see the mist or bubbles because the rate of CO2 being pumped into the tank far exceeds the rate it can dissolve in water.

I guess the same principle would apply to the case of pearling. The only difference is just CO2 being replaced by O2, which is produced by the plants due to photosynthesis.

Once again, I am not an expert in this field. I am just trying to explain things in a way that makes the most sense to me. Please correct me if I am wrong. I am willing to learn from new ideas.

Regards,
Tuan
 

Philosophos

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Pearling means that plants are growing fast enough that the leaf is producing bubbles of oxygen at a higher rate than can be diffused in the water. I'd imagine whether that level gets high enough or not has a decent bit to do with things like high flow rate which would reduce the amount of dead water area at the leaf.

In essence, pearling is more a statement of metabolism than it is ambient O2, though I'd imagine ambient levels would have SOME effect on the retention.

-Philosophos.
 

Biollante

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Whatever

Obviously I am no one, so whatever, I likely got it wrong. I never suggested that the water was 100% saturated with CO2, okay. :confused:

Biollante