# Why do my plants bubble after every water change?



## Rolo (Dec 10, 2003)

By hardness you mean KH? I'll just assume so and that means you have about 16 ppms CO2. Kind of on the lower side. 

Can we have a pH and KH reading of the water you use to change. If that has lots of CO2 - that should the reason. 

I'm surprised though that you have any pearling at all with 0 nitrates. How are your phospates and potassium.


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## jseal (Apr 3, 2004)

Rolo737 said:


> By hardness you mean KH? I'll just assume so and that means you have about 16 ppms CO2. Kind of on the lower side.
> 
> Can we have a pH and KH reading of the water you use to change. If that has lots of CO2 - that should the reason.
> 
> I'm surprised though that you have any pearling at all with 0 nitrates. How are your phospates and potassium.


Ok, I'll try to answer your questions as best I can:

My test kit (Aquarium pharmaceuticals) simply calls the test "Water Hardness" and reports it in PPM. It also gives a conversion to show it in German DH and I'll report both for you below.

Here are the numbers you needed:

Tank Water tested 2 days ago (6 days since last water change)
PH= 7.2, Water Hardness 150 (8.4 DH) 

Water from my tap (after dechlorination) (today):
PH= 7.4, Water Hardness 160 (8.96 DH)

Tank Water tested one hour after 20% water change today:
PH = 7.4, Water Hardness 160 (8.96 DH)

This is strange since by my calculation, these numbers mean that my CO2 content went from 16.7 ppm before the water change to 11.27 after the water change. An yet .... all the plants started to pearl after the water change. What am I missing ?

The only other thing I can think of that might be relevent is that I have about 1.5 inches of peat in my filter canister to help soften the water.

Oh ... regarding your point about Nitrates, my test kit colour indicator shows 0 ppm and the next step is 5 ppm. The best I can tell you is that my Nitrate level is betwen 0 and 5 and by my eye, very close to zero.


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## Rolo (Dec 10, 2003)

I still don't know what to make of your "water hardness," never heard of such an AP test kit. Is it an old one? If so I would recommend the delux GH and KH AP test kit.

With peat moss, the KH-pH-CO2 charts become in valid, so your CO2 levels in the tank are no more than a guess. We also don't even know if your "hardness test" is KH. This rules out the speculation of fluctuating CO2 levels with water changes.

What brand nitrate kit do you use. Nitrate kits are notorious for being very inaccurate. There are two though that many have verified to be very accurate - Redsea and Seachem. I personally like Redsea b/c its easier to read.

So, with all these holes, I can't give a for sure answer to why your plants are pearling after water changes. I guess the next thing is to go with more broad and common sense reply. 

With high light and CO2, you are making the plants very hungry for nutrients, and simply there is something in the tap they are getting, allowing for them to pearl. What are your phosphate and nitrate levels from the tap? Are you dosing any nutrients? K, PO4, traces, iron...? 

As you can see many holes need to be filled in. I would personally stop the peat filtration. 8 degrees GH or KH or "water hardness" isn't alot at all, and infact plants like high GH levels (hey, this might be the problem, your peat is removing Ca and Mg, and your tap replenishes it for the plants to pearl). Perhapes get some better test kits and if your not dosing, get to that too.

Hope this helps,
Chris.


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## jseal (Apr 3, 2004)

Thanks for your input Chris.

My water hardness and PH test kits from AP are a few years old. The Nitrate test is also from AP but I bought that just a 2 months ago.

I do not yet have a test kit for Phosphates or Potassium so I cannot fill in those blanks yet. I think I will try one step at a time and start by removing the peat from my filter. I will also get updated test kits for PH and KH and go from there.

Thanks
John


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## Jacan (Apr 24, 2003)

Your test kit must be measuring CaO because that will give the calculation from Water Hardness 150 to (8.4 DH). 
The test kit must be pretty old because CaO is actually water hardness as it was defined in the early days, and neither KH or GH, so get a new up to date test kit!

Plants can start to bubble after water change because cold aerated water under preasure from the tap has a higher concentration of air than in most aquariums, therefore due to higher temperature and lower preasure in the tank the air will bubble out of the water.


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## jseal (Apr 3, 2004)

Hmmm . That's interesting explnation Jancan. Thanks. 

You're right, my water hardness kit is quite old. I'll get a new one and see if I get a different reading. Is there a test kit out there or a test kit manufacturer that people would recomend?


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## Rolo (Dec 10, 2003)

Aquarium Pharm Deluxe GH and KH test kit.


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## Ajpearson170 (Apr 18, 2004)

I think iv read something about this before..... because your adding new water with less coz levels than the water allready your tank, the plants, I guess you could say get freaked out because there is a shortege of co2 than what there use to. This casses them to go in to hyper drive with the growing because you deprive the plants with co2, The plants starve for a lilttle amout of time and intake all the co2 they can. Then when the co2 gets back up they are use to intaking allot of c02 witch then they can produce more O2 bubbles. But i dont know i think soemthing to that effect is what is happening, but im new at this stuff so mabe if someone who reads this can explain it better.. or mabe im totaly worng lol


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## 2la (Aug 18, 2002)

Actually it's often the opposite: The tap water is supersaturated with CO2 and loaded with trace minerals, allowing a burst in photosynthetic activity that causes the plants to pearl (beyond the formation of bubbles from outgassing of dissolved gases) and stream. This is why in many cases if tap water is left standing, the pH rises steadily over the course of several hours.


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## Rolo (Dec 10, 2003)

In most cases what 2la stated is the correct theory, I don't know about the "freaking out" plant situation that AJpearson posted. Anyway, 2la, this doesn't appear to be the case, look at these numbers here Jseal provided us a few post up.



jseal said:


> Here are the numbers you needed:
> 
> Tank Water tested 2 days ago (6 days since last water change)
> PH= 7.2, Water Hardness 150 (8.4 DH)
> ...


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## Urkevitz (Jan 12, 2004)

If you pour a glass of water and let it sit bubbles for on the inside of the glass. I think the same thing happens in the tank, except the bubbles are forming on the plants. When I do a large water change bubbles form on the plants and the glass of the tank. The water may be high in Oxygen from the water change, so no more will dissolove, therefore it streams off the plants.


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## 2la (Aug 18, 2002)

Yes, I realize that, Rolo. I should have been more clear and specified that I was addressing the interesting theory Ajpearson170 brought up.

BTW, I'll be moving to the Twin Cities in a couple of months, so I hope you won't mind if I pick your brain a time or two in the near future.


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## Rolo (Dec 10, 2003)

Hey welcome to the twin cities, Minnesota! Wow, there are suddenly alot of people moving here. Well only two so far. You and Cruizer. Ask me any questions about Minnesota. It is quite different than the west coast, I moved here to Minnesota 7 years ago from Tacoma, WA.


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## SCMurphy (Oct 21, 2003)

Just as a way of distiguishing plant pearling from degassing pearling: If the bubbles are forming on everything, glass, plants, rocks, driftwood etc, then it is the water temperature/gas supersaturation effect. If the plants are the only things bubbling then it is the burst of photosynthetic activity due to raised levels of CO2, and possibly the introduction of lacking nutrients. 

Either theory can work, they have fairly distictive results, what is confounding is that the second one I list can follow on the heels of the first one.


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## aquaverde (Apr 15, 2003)

SCMurphy said:


> Either theory can work, they have fairly distictive results, what is confounding is that the second one I list can follow on the heels of the first one.


IME, it they both happen concurrently every water change. Not hard to tell- there's bubbles on everything and the plants are streaming. That's even in the low light tank.


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## malkore (Nov 3, 2003)

Sometimes bubbling after a water change isn't pearling at all. Due to temp differences, gases will form and bubble out of solution. It might be CO2, it might be O2.


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## hubbahubbahehe (Sep 13, 2003)

UGHHH...i finally found a thread that talks about this because I've observed this as well...... but it seems like there are so many possible reasons for this....


When my plants were in shock, I've seen them bubble like crazy before and I know they weren't photosynthesizing because they melted a couple days later....

When I do water changes, the bubbling of the plants occurs only on plants and not on the glass, driftwood, etc. 

Also when I fill the water in a new tank, I have also noticed that bubbles form on the glass. are those bubbles co2 or o2?


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