# JBL Permanent CO2 & PH Test Set



## btimmer92 (Mar 12, 2011)

I am not familiar with that test set, but I can explain the relationship.

I know that it uses a ph indicator called Bromothymol Blue. This is used to determine pH level

*Effect of CO2 and KH on pH:*
The more CO2 in your aquarium, the lower your pH will be.
The lower your hardness, the lower your pH will be
There are several other miscellaneous parameters that could effect pH

Drop checkers normally use what is called a reference solution, and pH indicator.

A reference solution is a solution that has an exact hardness degree that is known. In addition, there are no other unknown water parameters that could affect the pH reading. 

Every water parameter is constant, an known, except the CO2 level. The amount of CO2 is the only thing that is affecting the pH. Therefore, the pH reading in the drop checker solution correlates to an exact amount of CO2 .

For example, in a 4dKH reference solution of water and baking soda, a pH level of 7.0 indicates 30ppm of CO2. A 7.0 pH with Bromothymol Blue turns this solution green, and therefore when the drop checker is green, you have 30ppm of CO2. In conclusion, a drop checker test is just a pH test, in water that has no other variables beside CO2.

This being said, if your kit works, it tests both tank pH and tank CO2, and it is really measuring the pH of the tank water, and the pH of a separate chamber of water that does not mix with the tank water, but has a closed airspace between the the tank water, and the separate chamber.

However it looks like there is only one chamber of water, and one color reading (pH reading). Therefore your test kit is not measuring the true amount of CO2 in the tank. All it is doing is measuring pH of the tank. *Tank pH can be used to estimate CO2 amount, because of the statement above in red. But because of the two statements in blue, you cannot know the amount of CO2 for certain.* This is because there are countless unknown parameters in your tank water.


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## btimmer92 (Mar 12, 2011)

question 1. answer above. 
question 2. It will give you an exact pH reading, and a good estimate of CO2
question 3. By ADDITIVES, refer to the "miscellaneous parameters" described in the above post.

Somewhere you mentioned baking soda, that will increase your hardness levels. Therefore it is not a "miscellaneous parameter or additive"

you said your dKH is 10.64, refer to the spot on the chart that says 8-12 KH. Next to it, it says 7.0 pH, therefore if those two paramters have those measurements, your CO2 level is good. To use your kit for CO2, take your KH reading, find that square on your chart. If that color matches the color of your test water, your CO2 is probably good.

Your KH is ~10, find that square on the chart. The color of your test reading is more green than this, therefore, your CO2 may be high.

But, I forgot to mention, pH up and pH down would be great examples of "ADDITIVES". It could greatly screw up your CO2 reading. If you use these, you would not be able to use your test kit effectively. I am not sure how accurate this test kit is, because I have no idea what kind of substances in the water could be effecting you pH besides CO2 and hardness.


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## Disco Dan (Mar 17, 2011)

Thank you for your quick and excellent reply. Very much appreciated. 

The instructions say to use 1ml of water from the aquarium - which seems a little odd. I have yet to see it change colour from when first introduced so will keep an eye on water parameters as it says it will take up to three hours before it gives an accurate reading.


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## Hoppy (Dec 24, 2005)

That is just another version of a drop checker, but again the manufacturer doesn't understand enough about it to tell you that you must use distilled water containing a tiny bit of baking soda in it to give it a carbonate hardness of 4 dKH. Then, the green color indicates that you have around 30 ppm, actually somewhere between about 20 and 45 ppm. When you use tank water it isn't nearly that accurate.


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## mcubed45 (Jun 30, 2010)

Hoppy said:


> That is just another version of a drop checker, but again the manufacturer doesn't understand enough about it to tell you that you must use distilled water containing a tiny bit of baking soda in it to give it a carbonate hardness of 4 dKH. Then, the green color indicates that you have around 30 ppm, actually somewhere between about 20 and 45 ppm. When you use tank water it isn't nearly that accurate.


^^^
/agree

toss the instructions. order a bottle of 4dkh solution. fill the drop checker with that and a couple drops of your pH indicator solution.


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## Disco Dan (Mar 17, 2011)

*Well it has been a few days and I have had a fiddle around with my drop checker but I am still having a small issue.* 

I have used 1ml of tank water and 3 drops of the supplied reagent and it goes green. 

I have made up a 4kh solution, used 1ml and 3 drops of the supplied reagent and it goes green. Placed in tank 

*Both times it stayed the exact same colour day and night. *

Then I tried the same tests as above but using 3 drops from my PH test kit - again green and stayed that way day and night. 

*I have yet to see it change colour at all ! *

Tonight what I have done is refilled the checker using 4kh solution, the supplied reagent but this time I have stopped all the CO2. 

In theory - by morning the indicator should be blue. 

I then hope to slowly introduce CO2 until I reach a green indicative reading. 

At the moment I am feeling a bit ripped off spending almost $40 on a little plastic box with some green liquid in it and a couple of stickers. 

That and flipping algae is coming back and I had to dose the tank with more algaefix solution!


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## Disco Dan (Mar 17, 2011)

*Right, now I have not got a flipping clue what is going on. 

I turned off all three yeast reactors last night night and have been running a air powered foam filter to run off CO2 all day and night. 

Guess what... the drop checker is still green. 

So to sum up - the drop checker shows green when I add the reagent. Shows the same green when in the tank pumped full of co2 and also show green when tank is not full of co2. So what the flob is this thing actually doing?????? 

The only thing that I can think of is the drop checker is assuming when the tank has no co2 present the PH is 7.0 and any deviation from that is co2 influencing the ph - thus changes colour. If that is the case then a drop checker would only work if your tapwater is exactly 7.0 ph??? 

How does the drop checker KNOW what the PH of your individual aquarium is PRIOR to adding CO2 (that changes it) is? 

Having trouble getting my head around this now, thought it was pretty straight forward.*


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## btimmer92 (Mar 12, 2011)

That is exactly true. this test assumes all of your water parameters. That is why you use a calibrated reference solution in the drop checker, because it has exact parameters. You said you made a 4dKH solution, well you did it wrong... It should have a pH much higher than 7, and thus be blue when you first add the drops. How did you make it? I made my own with instructions from here I think and it's blue when I first add the drops.

You didn't just draw water that happens to have a 4dKH did you? because there can be a number of other things affecting the pH besides hardness.


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## Disco Dan (Mar 17, 2011)

btimmer92 said:


> That is exactly true. this test assumes all of your water parameters. That is why you use a calibrated reference solution in the drop checker, because it has exact parameters. You said you made a 4dKH solution, well you did it wrong... It should have a pH much higher than 7, and thus be blue when you first add the drops. How did you make it? I made my own with instructions from here I think and it's blue when I first add the drops.
> 
> You didn't just draw water that happens to have a 4dKH did you? because there can be a number of other things affecting the pH besides hardness.


I emptied the tank from my dehumidifier (which I assumed is pretty much pure) and added a tiny pinch of baking soda and then tested a sample which changed colour after 4 drops - giving me what I thought was a 4kh solution first time.


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## Disco Dan (Mar 17, 2011)

oh hang on

just noticed: dkh and kh 

Okay fiddled with my solution and it seems I had got mixed up. My test kit is in ppm not degrees. My solution was in fact only 2.2 degrees (40ppm).

I got it to 70ppm now which is 3.9 degrees. Close enough I hope. 

Put it into the drop checker and added three drops.... viola ! It has gone blue! 

Have put it into the tank - hopefully I will see an accurate reading!


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## btimmer92 (Mar 12, 2011)

I would use a standard reference. You can buy it on ebay for cheap if you don't want to make it. I made mine, but you never know how true it really is, and it was kinda a hassle.


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## OverStocked (May 26, 2007)

If the tank water or "4 dkh" water you made is green from the start, I would guess it really isn't 4dkh. 

The solution should be blue when you start. Do not use tank water. There are directions on how to make 4 dkh solution on this site in a few ways. It takes very very very little baking soda.


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