# Aquarium water inside drop checker



## igor.kanshyn (Jan 14, 2010)

Hi,

I just got my new good-looking drop-checker. 


> Instruction
> 1. Turn drop checker up-side-down and place 3-5 drop of test solution into the drop checker.
> 2. Use a pipette (not include) to inject *tank water* into the drop checker.
> 3. You will see the color change on the solution according to Co2 content in the tank water.
> 4. Turn drop checker up-side-down again carefully, and place the drop checker inside the tank below water level.


After reading the instruction I got confused.
It says that I need to put an *aquarium water* into a drop-checker. Not a distilled water or KH 4 solution water. 
So, this drop checker is, in fact, a pH indicator 

At the same time other similar items on eBay have other instructions.

I also not sure how many water I should add. A bottle with "Co2 Test Solution" says that I need to use 5 drops of it and then add water to a required level. But where is this level?


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## Darkblade48 (Jan 28, 2008)

You must use a reference kH solution (i.e. 4 dkH reference solution), if you want to use the drop checker for its intended purpose.

Distilled water/RO water/aquarium water/tap water is not to be used.

You need to fill the drop checker about halfway full; ideally, you want the maximum surface area exposed so that the rate of CO2 exchange occurs faster. For a bulb-type drop checker, this would be the halfway point of the bulb.

For the bromothymol blue indicator solution, you can add anywhere from 3-8 drops. Adding very little will help conserve the reagent, but you may not get a very deep colour, and it may make reading the drop checker difficult. Adding more will not affect how the drop checker works. Of course, you don't want to add so much to the point that the entire solution is opaque, however.


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## waj8 (Jun 30, 2010)

You are not the first person to be confused by those totally incorrect instructions.


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## igor.kanshyn (Jan 14, 2010)

Thank you very much, Antony.

I was sure that something wrong with that stuff 

I have KH 4.0 salt. It came with pH test pen and I can use it.
So, it will make KH 4.0 solution using distilled water and that KH 4.0 salt. Then I will fill the cap to a half and add several drops of a blue test liquid. It's good that its concentration is not important.

Is it easy to find out that I have too much CO2?
I read here that drop checker turns yellow at 70 ppm of CO2.
I'm afraid all my shrimps will be several times dead at this point.


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## Darkblade48 (Jan 28, 2008)

Using a 4 dkH reference solution, anything higher than approximately 45 ppm will appear yellow.

Again, I would not use eBay sources that instruct to use distilled/tap/aquarium water instead of a kH standard as your reference source.


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## camboy012406 (Jun 11, 2010)

hi guys how do I know if the seller in ebay can be trusted?? coz im planning to order online but im afraid to try.. any suggestion??


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## igor.kanshyn (Jan 14, 2010)

Darkblade48 said:


> Using a 4 dkH reference solution, anything higher than approximately 45 ppm will appear yellow.
> 
> Again, I would not use eBay sources that instruct to use distilled/tap/aquarium water instead of a kH standard as your reference source.


Thanks again.

I was attracted by a nice view of a glass drop-checkder. 
"Co2 Test Solution" that they provide, should be similar to all the others solutions.
So, having a nice equipment and your professional help I can do virtually everything 

I will fill this drop-checker correctly tomorrow and write about results.


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## igor.kanshyn (Jan 14, 2010)

camboy012406 said:


> hi guys how do I know if the seller in ebay can be trusted?? coz im planning to order online but im afraid to try.. any suggestion??


I bought crazy amount of cheap things in eBay. Something I got crap, but it was not happen often. And I was *always* getting a refund or a replacement item if I was not happy.
The only problem is shipping. It takes 2-3 weeks usually. Two times I got my items after two month waiting 

Tip, try to buy new items from companies, it's difficult to deal with individuals.


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## Darkblade48 (Jan 28, 2008)

camboy012406 said:


> hi guys how do I know if the seller in ebay can be trusted?? coz im planning to order online but im afraid to try.. any suggestion??


Mainly, you can look at their references. You want a seller that has both a high number of reference, but also a high percentage of quality (positive) references. I usually do not deal with anyone with less than a 99% positive feedback rate.



igor.kanshyn said:


> "Co2 Test Solution" that they provide, should be similar to all the others solutions.


The solution they provide appears to be bromothymol blue only.


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## igor.kanshyn (Jan 14, 2010)

Oh, it was completely dull thought that pH testing pen had 4 dKH solution in a package. Of course, it has pH 4 solution 
I'm so stupid 

I will go to a kitchen and search for baking soda ....


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## igor.kanshyn (Jan 14, 2010)

It's strange.

I've made 4 dKH solution, I hope.
I've added 1.2 ml of baking soda to 1L of distilled water.

And I'm trying to test its KH by Nutrafin KH test kit. I'm adding drops of a blue testing solutions into my 4 dKH solution and mixture doesn't turn yellow.
It might can't be tested this way.


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## Darkblade48 (Jan 28, 2008)

1.2 mL of baking soda? Perhaps you mean 1.2 g?

1.2 g of NaHCO3 into 1 L of distilled water will make a 40 dkH reference solution, not a 4 dkH reference solution. You will need to do a tenfold dilution.

Also, unless you were using high quality (and new) reagents, your kH solution will probably be slightly off.


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## igor.kanshyn (Jan 14, 2010)

I don't have scales. I read that one teaspoon of baking soda is 5 ml. So, it has the same density as water.
Yes, I used 1.2 g or 1.2 ml for 1L and then dissolved 5 ml of this mixture in 50 ml of distilled water again.

I've tested my solution again (I might get a water from a wrong bottle before) and got Kh 4 with my API test kit 

There is another problem with drop-checker I purchased. It has odd CO2 reagent. It doesn't look like _bromothymol blue_. After adding into KH 4.0 solution it gives maroon almost black colors  It looks like a reagent from my API PH hight range test kit. It gives different hues of red.

I used a reagent from my API PH low range test kit for now. Mixture look bright blue. Let's check it after being several hours in a tank with CO2 injection.


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