# Chlorine toxicity



## Edward (May 25, 2004)

Here is a picture of Limnophila aromatica damaged by chlorine from the tap. The new leaves are curled and small. This abnormality was not happening when the tap was filtered over a carbon cartridge.










Do you have similar experience?

Edward


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## Cavan Allen (Jul 22, 2004)

This happened to leaves that were already normally formed? What were the circumstances surrounding it? I've left plants in chlorinated tap water plenty of times and have never seen anything like that. Then again, not all tap water is the same...


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## Edward (May 25, 2004)

Hi Cavan

This top section developed after the chlorinated water change in the following 3 days. Old growth was not effected. Before that, water changes were done frequently to avoid rapid water parameter change over the carbon cartridge. The lighting was 2Wpg PC in reflector above 50gall aquarium. 

Edward


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## R0bert (Jan 23, 2006)

Carbon removes more than just chlorine. Has the hardness changed at all?


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## Edward (May 25, 2004)

Hi Robert
Carbon filtration has no effect on hardness.


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## kekon (Aug 1, 2005)

I have very similar effects on some leaves. I use CaCl2 to reconstitute RO water. Ca is about 20ppm and chloride 35ppm. It seems to me it is too high.


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## david lim (Mar 30, 2004)

It seems that some controls need to be setup before concluding that Chlorine is the culprit. I'm not saying that you're wrong, Edward, but it would give you a much stronger argument to make controls. Although impossible, since tap has lots of things in it, would be to remove the chlorine only from the tap while leaving everything else and seeing if there's a change in the growth habbit. For another control I would take your carbon filtered water, which has shown good growth, and replenish it with chlorine, and then look at the effects. And finally, to isolate chlorine, I would take R/O water, replenish it with chlorine at varying doses from 1-50 ppm and see if there's a differential effect based on the concentration of chlorine to the growth habit of your plants. Lots of work.... but just thoughts...

David


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## plantbrain (Jan 23, 2004)

Edward said:


> Hi Cavan
> 
> This top section developed after the chlorinated water change in the following 3 days. Old growth was not effected. Before that, water changes were done frequently to avoid rapid water parameter change over the carbon cartridge. The lighting was 2Wpg PC in reflector above 50gall aquarium.
> 
> Edward


What was the Chlorine or Chloramine levels in the tap and what fraction of water change did you do, eg what were the levels in the tank and time of exposure??

New growth impacts of chlorine have several potential issues.

Regards, 
Tom Barr


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## plantbrain (Jan 23, 2004)

kekon said:


> I have very similar effects on some leaves. I use CaCl2 to reconstitute RO water. Ca is about 20ppm and chloride 35ppm. It seems to me it is too high.


No, don't assume these two are the same, they are not.

Free Chlorine and Chloride anions are very different toxicologically.

Let me ask a simple question, what's the difference between a chloride anion and chlorine anion?

Hint : it has to do with gaining an electron.

Regards, 
Tom Barr


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## Chris S (Feb 27, 2006)

Hi, Im actuall replying to the origional post . I have had this happen in my tank htis week. Green hygro tops after a water change 50%. Look the same as your leaves curling downward. This phenomanon shows up in the morning and is gone by the time i get home from work. Happens only after a water change now that u mention it.
What type of tapwater conditioning additives are good to use with our planted tanks?


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## kekon (Aug 1, 2005)

The only tap water parameters in my region I know are mainly Ca and Mg levels:
Ca = 55 ppm
Mg = 15.5 ppm
NO3 = 10
PO4 = 0.1..0.25 ppm

Unfortunately, other elements are unkown. In the past I used tap water mixed with RO one in 1:1 ratio. Most of my plants grew quite well apart from Cabomba Caroliniana. Now I began to use only RO water reconstitued as follows:

Ca = 20 ppm (12 ppm Ca from CaSO4, 8 ppm from CaCl2)
Mg = 5 ppm (anhydrous MgSO4)
NO3 = 10 (dosed from Ca(NO3)2 )
PO4 = 1.0

NO3 and PO4 levels are kept at levels given above all the time.

The problem with using CaSO4 is that it adds much SO4 and I really don't know how it affects plants. 
That's why I try not to add more than 20 ppm Ca. I was told not to care about SO4 but I donn't know how it will affect my plants.
Now I have to wait and see how plants will behave in such conditions.
When I started to use RO water something's wrong happened to Rotalla Wallichi and Bacopa caroliniana - they grow very, very slowly. The only positive thing with Bacopa is that it looks very healthy. Rotala pracitally "stands still" and its tops are being stunted and "burned" all the time. Maybe the problem concerns Ca/Mg. I'd like to increase Ca up to 30 ppm and see the effects. Lately I've discovered how to dissolve CaCO3 without using CO2.
Namely, one can buy CaCO3 in 1..3 mm pellets form.
You can put some pellets into a tubing (diameter about 3..7 cm). Obviously the bottom of the tubing should be clogged with something that will protect the pellets against falling out (a piece of sponge etc.)
Then, simply put RO filter outlet pipe into the top of the tubing allowing RO water to flow slowly through CaCO3 pellets put in the tubing. RO water will flow out from the bottom of the tubing and collect in a barrel. The longer the tubing and the bigger amount of CaCO3 the higher level of Ca will be. In order to further increase Ca to higher levels (when the barrel is full) one can use small pump to pump water in a closed circuit in the barrel through the tubing.
I carried out an experiment and allowed RO water to flow through a container filled with several grams of oridinal CaCO3 and I achieved GH = 2. This is low because CaCO3 in its typical "sand" form is not well water-permeable and the most of water didn't flow through it.


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