# Why do my plants pearl after a water change?



## philipraposo1982 (Mar 6, 2014)

I don't think that's pearling. I am petty sure its trapped dissolved gasses in the tap water.

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## The Big Buddha (Jul 30, 2012)

I can see bubbles forming on large leaves then releasing, then more bubbles forming.


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## WaterLife (Jul 1, 2015)

There was this thread a while back.
http://www.plantedtank.net/forums/8...-plenty-oxygen-fish-when-plants-pearling.html

I believe there was some talk about water changes and pearling. Don't quite remember if there was a concrete answer to the pearling (or false pearling) after water changes. Some of the info, might be interesting to read though.


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## Immortal1 (Feb 18, 2015)

Seems when I do a water change I get the same false pearling. When I take the time to de-gas the water, the pearling does not seem to last as long so, I guess there is some validity to the statement of false pearling.


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## discuspaul (Jul 27, 2010)

That wasn't 'pearling', that was simply mini air bubbles (oxygen) from the tap water attaching to the plant leaves while filling the tank, and being concentrated on them as bubbles afterwards. Happens all the time.


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## The Big Buddha (Jul 30, 2012)

I would think the water has already de-gassed since it is RO that I take from my reservoir where it has been for a week with a strong circulation pump running 24/7. I can actually see the leaves produce bubbles where bubbles are not present.


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## philipraposo1982 (Mar 6, 2014)

Well now I am confused.

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## WaterLife (Jul 1, 2015)

Yeah, I don't have a definitive answer either. As noted in the thread I linked (last post in the thread), I too have had plants pearl/false pearl after a water change, in which it looks like the plants actually did produce the bubbles, not simply bubbles sliding/rising up against the plant. And these were undamaged plant areas as well. 

My best guess is somehow the water change itself either boost plant growth/production. Or the water does indeed become too saturated in gasses that the water solubility expels the excess gases in the form of undissolved bubbles. So the gasses that the plant is normally producing (o2 during photosynthesis) is no longer dissolved o2 (which are normally "invisible", unless you already have plants that pearl), are now being released undissolved (which are now visible) since the solubility of the water has already been reached (which is the same as 'true' pearling).

But I'm no expert. Just giving it a guess. Would be simple tests to rule my guesses out though.


Ehh, just thought I might link @essabee comment from the thread mentioned if no one read it
http://www.plantedtank.net/forums/8...-fish-when-plants-pearling-2.html#post8480850
might be interesting info for the topic


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## flinters17 (Jul 1, 2015)

It probably comes down to two things:

Firstly, when you put new water in you likely are pouring it in from some height above the water, causing lots of air to dissolve in the water for a short period of time. As is equilibriates with the room the plants will continue producing O2 as they do, and since there is so much already in the water due to the pour, it bubbles.

Second, when you cut the stem of some plants they lose O2 and other gasses more rapidly than they do through the leaves, which may account for some of it.

These are my best guesses though, so it could easily be something else. I've noticed it too.


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## burr740 (Feb 19, 2014)

Some of what you see is definitely "real" pearling. The reason plants pearl after a water change is because the tank water gets saturated with O2. The oxygen produced from photosynthesis cant absorb and becomes visible to the naked eye in the form of a bubble.

But, all those micro bubbles that show up on the glass and everywhere is just oxygen doing what discuspaul said.


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## Straight shooter (Nov 26, 2015)

Correct Burr740. Tap water also usually contains a higher dissolved CO2 level. That doesn't explain the OPs situation, his water should have equilibrated (see Henry's law of the constant), and tank water and new water should be the same CO2/O2 concentration. BUT there are many more DOCs in tank water which plants also use.


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## yakal (Sep 4, 2015)

IME there are certain plants that right after trimming oozes some form of gas in the form of bubbles right where the stem was cut. this might be the reason why too (maybe) and sometimes it doesnt float to the surface right away and sometimes attach to leaves.


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## discuspaul (Jul 27, 2010)

I think the "strong circulation pump running 24/7" in the OP's RO water reservoir has something to do with what's happening here - -i.e. accumulation of 02 in the water reservoir being released when water is pump transferred to the tank for wcs. That's my guess.


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## The Big Buddha (Jul 30, 2012)

discuspaul said:


> I think the "strong circulation pump running 24/7" in the OP's RO water reservoir has something to do with what's happening here - -i.e. accumulation of 02 in the water reservoir being released when water is pump transferred to the tank for wcs. That's my guess.


But when I did a water change of 30% last week on my 65g there was no pearling ( or bubbles) but it is lower light, or when I did one the week before on my 40b.

.


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## discuspaul (Jul 27, 2010)

The Big Buddha said:


> But when I did a water change of 30% last week on my 65g there was no pearling ( or bubbles) but it is lower light, or when I did one the week before on my 40b.
> 
> .




Well, all I can say is that we shouldn't expect that to happen each & every time we do a wc in your circumstances.


Perhaps conditions within the reservoir & within the tank itself were somehow particularly conducive to that occurring then. Who knows really.
Just saying that it could be certain circumstances that triggered it. 


I still don't think it was pearling, which, to my knowledge, requires a significant length of time exposure to CO2, the pearling begins slowly and builds up, and it takes a long time to cease happening and dissipate. Doesn't seem like those conditions were present when you experienced what you did.


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