# Massive Pearling After W/C?



## DJKronik57 (Apr 17, 2006)

My plants in my 29 Gallon tank started pearling like crazy right after I did a 25% water change. Is this normal? What, if anything does this mean? I almost never see them pearling day to day, even though I have 130W. It's so exciting to see!!


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## Gonzofish (Mar 26, 2005)

Your diy co2 isn't cutting it. If your tank is algae free and plants look healthy, then I wouldn't worry about it. Otherwise, invest in a canister.

Best of luck.


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## DJKronik57 (Apr 17, 2006)

Hmm. The plants have been growing steadily, my christmas moss is growing like crazy which it wasn't before I added the CO2, and the only algae problem I have is green spot algae on the tank walls and some java fern leaves which is due to a phosphorous defficiency.

Right now I'm using a big juice bottle for a generator and the Hagen bubble ladder for a reactor. I have no surface distubance and use an internal filter. The bubbles are 85% gone before they reach the top of the reactor and go to the surface. The mix is about a week and a half old and I'm getting a bubble every 15 seconds. So does this mean I just need more bubbles (i.e. another generator)? Or do I need a more efficient reactor?

A CO2 canister is out of the budget range right now and for the forseeable future. :sad:


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## trenac (Jul 16, 2004)

My tanks have massive pearling after a water change too, due to the fact that our public water system has a lot of C02 in it. The amount of pearling is always back to normal in a days time.

The only way to know if you have enough C02 in your water is to take your KH & PH readings and use this chart. Keep your levels at a steady 20-30ppm at all time, the closer to 30ppm the better. If you find your levels lower you may want to think about adding a another bottle to your setup.


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## DJKronik57 (Apr 17, 2006)

See the thing is, I get absolutely no pearling otherwise. And according to the chart and the calculator on that page, I'm at or above 30ppm, which I highly doubt. If it was that high, with 4.5wpg, shouldn't I be seeing pearling? I'm dosing Flourish, Phosphate, Potassium, and Excel regularly. Is there any other way to measure CO2?


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## trenac (Jul 16, 2004)

It could be that your test kits are off and not given you a accurate reading, causing the chart to show you have more C02 than you really do. Another method some use is to slowly turn the C02 up day by day until the fish start to gasp at the surface then turn it down a bit. However this would be very hard to control with DIY C02 injection. You may just need to add another bottle or change the mixture to see if that helps.


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## Bert H (Mar 2, 2004)

Another way to test your CO2 levels is the pH measurement in tank and after degassing. Take a sample of your tank water and let it sit out for 24 hours at room air. Measure the pH. Your target pH should be 1 pH unit below your degassed measurement to yield in the 30 ppm range. This method bypasses things that can throw off the kh/pH relationship. 

You have a lot of light for a 29gal tank. If this is an established tank, and all appears to be well from what you mention, then don't worry about it. 'If it ain't broke, don't fix it.' If this is a newly established tank, you really should be aware that you have to make sure you maintain all your nutrient levels good with such high lighting or else, you're inviting algae.


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## kdh (Mar 11, 2006)

I don't want to insult anyone's intelligence here but I've read posts about pearling after water changes before and the thought that always comes to mind is...

couldn't it just be bubbles? My tanks are often full of bubbles after a waterchange depending on how I pour the water in or where my python is pointing.

I realize there's a difference and if I saw your tank the difference could be obvious but I just had to get that question off my chest. 

Sorry


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## plantbrain (Jan 23, 2004)

kdh said:


> I don't want to insult anyone's intelligence here but I've read posts about pearling after water changes before and the thought that always comes to mind is...
> 
> couldn't it just be bubbles? My tanks are often full of bubbles after a waterchange depending on how I pour the water in or where my python is pointing.
> 
> ...


Generally most folks can see if their plants are pearling vs the bubble just sticking to things. You see an increase in water clarity.

You can also see the growth spurt as well as a reduction is algae, like GSA if they add plenty of PO4.

If done in the AM,the tank wikk have far more pearling late in the day, that is a CO2 issue, the bubbles do not increase from mere water changes, that is when you know the water change added CO2 to an otherwise CO2 limited tank.

Regards, 
Tom Barr


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## NE (Dec 10, 2004)

I believe that the massive pearling after the water change is not due to the CO2 level in the added water, I think that it is because of the oxygen level of the added water.

This is how i see it:

The normal pearling does not start until the water has reached a "high" level of oxygen saturation, this is why there is no instant pearling when the lights go on, it takes depending on the setup half the day.

The water you are changing with are normally extremely saturated with oxygen, you can actually see the gas if you bend the hose a bit then you get a mist of bubbles out from the hose.

This means that the water in the tank after the water change has that high oxygen saturation that every single part of oxygen the plants produce will be visible as a bubble.

http://zoone.se/main/blog/oxygen-level-over-one-week


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## taekwondodo (Dec 14, 2005)

I don't know about either of those theories... I could buy it if I had well water (used to have a well in VA that had so much CO2 in it that it was corroding the copper pipes in the house...), But I make 15-20 gallons of RO, stored with little exposure to the atmosphere - The RO certainly doesn't have a whole-lot of O2 or CO2 in it... yet, when I do a change I get massive pearling also.

Could it be that the redox of the water replaced is much higher than what is pulled out, and hence the plants respond/photosynthisize better?

(that's my theory and I am sticking to it  ).

- Jeff


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## Elkmor (Mar 30, 2005)

taekwondodo said:


> RO, stored with little exposure to the atmosphere ... when I do a change I get massive pearling also.


I have the same results. My tank is anything but not CO2-llimited. 

I also niticed that "pearling" comes from unclean parts of glass even if I use RO water. It seems that gass from aquarium water comes out, or some gasses comes in while new water contacts with old aquarium water, involding a lots of bubbles.


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## JLudwig (Feb 16, 2004)

Well, here's my theory. A lot of us have chloramines in the tap targeted to 2-4 ppm Cl (http://www.reefkeeping.com/issues/2003-11/rhf/feature/index.php). 3 ppm Cl gives 1.18 ppm N. Assuming the dechlorinator complexes with the ammonia in a bioavailable way, that is effectively adding 5ppm-NO3 but in a much higher energy form, NH3. I think a large W/C is a good shot of energetic nitrogen just due to breakdown of the chloramine.

Cheers,
Jeff


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## taekwondodo (Dec 14, 2005)

Doesn't fit why someone with RO gets massive pearling when a change happens (i.e., no Chlorimines). I'm stuck on the redox theory...


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## DJKronik57 (Apr 17, 2006)

taekwondodo said:


> Could it be that the redox of the water replaced is much higher than what is pulled out, and hence the plants respond/photosynthisize better?
> 
> (that's my theory and I am sticking to it  ).
> 
> - Jeff


What do you mean by redox of the water?

I think JLudwig has a valid point. I'm guessing I do have chloramine in my water since my water is Boston city water. But would the plants absorb and react that quickly to NH3? Is it safe for the fish? I'll have to check my dechlorinator when I get home because it might be a brand that binds the NH3. If this is the case, we're back to square one.


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## plantbrain (Jan 23, 2004)

Here we go again, some one wants to suggest the NH4 is helping, well, add some NH4 if you feel that sure. Newbies and folks that are not careful, don't bother, you'll kill off all your fish and have a nasty algae bloom. I have tanks without fish to do stuff like this.

RO water change still have a fair amount of CO2, even if it's removed fast, it still gives a nice boost, but that's not the 1/2 of it nor the significant part.

When you do a large water change, do the plants get exposed to the air or not? How do you think that effects the plants in terms of CO2 if they are limited prior?


Regards, 
Tom Barr


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## taekwondodo (Dec 14, 2005)

Tom,

My tank is normally pH of 6.3/6.4 with a dKh of 4-5 (estimate 50-60ppm - I had the pH down to 6.0 a while back and the glosso was growing tall (220W PCFs)). The RO water probably lessens the CO2 amount in the tank (I doubt the RO is over 50ppm CO2...).

Other than increasing the redox (no, I don't measure it, just a guess) the only other thing I can think of would be the increase in O2 (I pour the water in...).

- Jeff


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## BryceM (Nov 6, 2005)

How about this..... You'll see pearling when a liquid becomes saturated with a gas. When the gas comes out of solution it usually forms on an irregular surface. Ever try to boil water in a perfectly smooth container? New water can induce pearling for a number of reasons. If it contains a ton of CO2 and your tank is generally carbon limitted, the plants get a rapid "shot in the arm" and start cranking out O2, which saturates the water and you see pearling. If the water you add is saturated in O2 (or even supersaturated) you might get pearling. If the water you've added contains something that your tank was deficient in, plant metabolism will increase and you'll see pearling.


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## JLudwig (Feb 16, 2004)

plantbrain said:


> Here we go again, some one wants to suggest the NH4 is helping, well, add some NH4 if you feel that sure. Newbies and folks that are not careful, don't bother, you'll kill off all your fish and have a nasty algae bloom. I have tanks without fish to do stuff like this.


I do plan on adding NH4, I'm quite confident my plants and biofilter can handle it and even if something terrible algae-wise happens I know how to take care of almost anything, just requires patience and elbow grease.

Jeff


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## Elkmor (Mar 30, 2005)

Can it be because of temperature difference?


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## DJKronik57 (Apr 17, 2006)

No, the temperature of the new water is within 1-2 degrees of the old water, so it's not that.

At least in my case, I think it's just an excess of CO2 from tap water mostly. Excess CO2 in the water would cause more photosynthesis and creation of oxygen till the CO2 levels dropped back to what they normally are. I use Aqua Plus by Hagen as a water conditioner and I'm pretty sure it binds ammonia, so I doubt that is playing a major role.

I'm talking about bubbles visibly coming from plant leaves as well, not bubbles on the glass or other rough surfaces.

I'll try degassing a cup of water as suggested and try to measure my CO2 levels more accurately than the chart. In the end, I think I'll have to add another CO2 generator. I'll let you all know the results of both!


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## plantbrain (Jan 23, 2004)

taekwondodo said:


> Tom,
> 
> My tank is normally pH of 6.3/6.4 with a dKh of 4-5 (estimate 50-60ppm - I had the pH down to 6.0 a while back and the glosso was growing tall (220W PCFs)). The RO water probably lessens the CO2 amount in the tank (I doubt the RO is over 50ppm CO2...).
> 
> ...


High light does not in anyway imply tall Gloss or short Gloss.
The leggy appearence is due to Phytochrome and shading, not intensity.
O2 and redox are related. If the RO water is allowed to degas for 24 hours prior............then yes, the other assumption is that the CO2 popm is really what you state. No error on your part, but the test and other assumptions in the testing method can get you in trouble.

How many times have we seen recently where folks have 100-200ppm CO2 ranges and things look fine?

Regards, 
Tom Barr


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## plantbrain (Jan 23, 2004)

JLudwig said:


> I do plan on adding NH4, I'm quite confident my plants and biofilter can handle it and even if something terrible algae-wise happens I know how to take care of almost anything, just requires patience and elbow grease.
> 
> Jeff


Good, now newbies, do not go and do this, Jeff is well aware!
UV is about the best tool for the GW if you over do it.
We tried this in our club about 5-6 years ago. 
No one is doing it any longer, it did not produce the massive pearling folks often see associated with the Water changes, if it was the cause, then it never manifested itself, I'd say it was nothing more than a passing fad for us here. It was playing with fire for little gain.

The water changes and intense pearling is the same effect I got when I started using CO2 mist methods.

That same response I have seen upon the addition of a treatment. 
So...........that would seem much strong observational evidence that the cause is due to CO2, not NH4, or these other factors.

Colder water will hold more gas, but not that much more.

Regards, 
Tom Barr


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## bonklers (Sep 24, 2005)

If it is because of the CO2, then why does my tap water have higher PH than the water in my tank (both have the same KH)? This means that the CO2 in tap water should be less than in the tank.

I do a 70% WC weekly so when it comes to KH I suspect it won't be much different than the tap water. Still whenever I do a WC, I measure PH 7.3, and my computer is set to PH 6.8.


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## plantbrain (Jan 23, 2004)

bonklers said:


> If it is because of the CO2, then why does my tap water have higher PH than the water in my tank (both have the same KH)? This means that the CO2 in tap water should be less than in the tank.
> 
> I do a 70% WC weekly so when it comes to KH I suspect it won't be much different than the tap water. Still whenever I do a WC, I measure PH 7.3, and my computer is set to PH 6.8.


True, but don't your plants get exposed to the air when you do 70% water changes? Off hand I've seen high pH water with high CO2 as well.
But I'm not quite sure if this applies here. My gut say no. But I might be wrong here.

I'm racking my brains as they added ployphosphate to reduce scale, but that was downstream from the treatment plant. Some places do partial lime softening, this sends the pH very high(OH-'s are all over), then the CaCO3 preciptates out at about a pH of 10.1. This is also how shells are formed with coral, snails, calcerous algae.

They often add CO2 to lower the pH afterwards.
This in effect adds more CO2, but still has a higher pH.
Pressure water or well water sources almost always have more CO2 as well.

Still, I'm not sure and have no clue as to thwe tap water sources you have.
I would guess *the plants being exposed for a little while to the air for the increased pearling*.

PO4 additions can cause increases in pearlign you can certainly see, as dramatic as adding CO2 if everything else is in good shape and the PO4 was limited prior, I've never found that to be the case with NH4.

That might be part of it as well.

Regards, 
Tom Barr


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## bonklers (Sep 24, 2005)

Ok, I guess measuring CO2 indirectly with PH meter and KH isn't very reliable. If there was such a thing to measure CO2 directly, then it would be interesting to measure the CO2 right before and after a WC. And yes a lot of the plants do get exposed to the air when doing a WC, be it directly (for high big plants) or indirectly via fine bubbles which are created by turbulence/pressure/all the mechanical processes of tap water going into the tank. 

The big question to me is that if the massive pearling is due to the tap water itself, or due to the proces of a WC. If it's because of the "new water" then there is some nutrient depleted (CO2, micro/macro nutrient etc) at some point during the week. 
I account "Plants being exposed for a while to the air for the increased pearling" to the process of a WC itself. Just like the fine bubbles that's produced when doing a WC.

To see which of the two is responsible for the massive pearling, I come to think of a low budget experiment. What if I do a WC with old water. So I drain 70% away from the tank, and put it back in the same way as I do with tap water: with a small hose under pressure. If I get massive pearling then it's due to the process of a WC itself, if I don't get pearling then it's due to the "new water". Ofcourse I cant do this experiment, at first I have to have a 80 gallon tank to store the old water, and a pump which gives me the exact pressure as my tap water does. What do you guys think about this "experiment"?


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## DJKronik57 (Apr 17, 2006)

The results of degassing a cup of tank water for 24 hours shows that while my tank pH levels are around 7.0, the pH in the cup was around 7.8. Not quite the 1pH difference to reach 30ppm CO2 Bert H suggested earlier. Anyone know how accurate this is?

Also, my plants were not exposed to air while doing the W/C. I only did a 30% change.

I am interested in Bonklers' experiment, it seems like it would at least shed some light on whether or not it's a concentration of gas in the water or some nutrient from tap water that's causing the pearling. I'd like to try it, but I don't have any pumps to use. Perhaps you could just siphon some water out into a tub and then pour the water back in at roughly the same rate?


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## BryceM (Nov 6, 2005)

DJK,

A 0.8 pH drop will put you at about 19 or 20 ppm CO2. It's a logarithmic scale so a 1.0 drop in pH is actually a lot more a 0.8 pH drop. The method should be quite accurate IMO.

One caveat. Obtaining a 1.0 unit drop indicates an appropriate and reproducible quantity of CO2 for good plant growth. Is the actual concentration of CO2 once you achieve this exactly 30ppm? It depends on the actual equilibrium concentration of CO2 in water exposed to the atmosphere. Since there is some debate on this exact number, I can't be certain that a 1.0 pH drop represents exactly 30 ppm CO2. It does indicate that you have 10 times the concentration of CO2 at atmospheric equilibrium. A pH drop of 0.8 units will equal 6.3 times the atmospheric concentration.


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## plantbrain (Jan 23, 2004)

If you do see better growth/pearling after a water change, it means generally you can improve the method you are doing during the rest of the week, this is generally a CO2 related issue if you use something like EI for dosing.
So you can add more, or change to mist type of method.



Regards, 
Tom Barr


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## DJKronik57 (Apr 17, 2006)

Tom,

What exactly is the mist method? Do you mean a CO2 reactor that creates a mist?


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## NE (Dec 10, 2004)

I dont think the air exposure is the key here, when i do a water change the plants are never exposed to air and i still get the massive pearling.
I fill the water at the same time and the same amount as i take it out.


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## DubSack (Mar 20, 2006)

ya, Your pearling insnt "true" pearling. If you see bubbles stick to the glass and everything else in the tank then it's just because your tap water has really high o2 levels. If you only see pearling after waterchangs, then its not pearling.


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## davej (Mar 5, 2006)

Don't know if I am flogging a dead horse here, but I also have the same heavey pearling after a water change. I was wondering if it had anything to do with the fact that the new water (change 50-60%) is softer (2-3degrees). Maybe it is a different osmotic pressure on the plant cells or something???????????? Just throwing this out.


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## 247Plants (Mar 23, 2006)

I think its because municipal water systems are pressurized and therefor hold more gasses then water that has been sitting out and when you put it into your tank it releases the gasses contained......which also contains a lot of CO2....


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