# Very confused about KH testing. (API)



## Doratus (Sep 14, 2010)

I'm trying to determine the KH of my planted 20g aquarium but the test results I'm getting are confusing. It takes about 20 drops of the solution (one drop at a time, capped and inverted after each drop) to change from blue to orange. I never got to yellow, which is what the instructions say to do. I fear I will use half the bottle of test solution to get to yellow. So is my co2 really at like 400ppm? 

That seems insanely high to me considering I only have a DIY coke bottle co2 setup and it has only been in place for a couple of weeks.

Thanks for any opinions or suggestions. My ultimate goal is to determine the co2 levels in my tank. If there is any easier way then to test PH and KH I'm all for it.


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## Big Dog (May 17, 2010)

I have run into this problem also with these test kits. They are a big pain to work with at times. Your water could be that hard.


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## WhiteGloveAquatics (Sep 3, 2009)

36 drops on my initial test, went and bought an RO unit, now im lucky to get 6 drops.

when it goes from blue to orange there are a few more drops left to get to yellow.

I use equilbrium,alkaline and acid buffers from seachem to keep my Gh and Kh in check, also run Co2 on the tank.


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## Big Dog (May 17, 2010)

R/O water is the best way to go. There is a store I like to order my R/O parts from. The store has great prices on line and are very helpfull. R/O water is all I use on my aquariums.


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## beaslbob (May 29, 2009)

There is a co2 test available.

the kH can be that high I just go for the color change and assume that is it.


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## Big Dog (May 17, 2010)

You been around aquariums for a long time. If the fish or the other living things in your aquarium are not having any problems. I would not worry to much about the KH. Some fish and plants can handle hard water with out any problems.


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## Doratus (Sep 14, 2010)

I did a second KH test, and this time it only took 9 drops. I'm trying to use this chart below but of course my digits aren't on there. I'm generally pretty good at math but I can't follow the succession of this chart. Maybe it's because I haven't had my coffee yet. Can anyone help me out?

I THINK I'm at about roughly 4ppm. (which is a bummer, haha)

my PH = 7.8
my KH = 9.0

-----------------------------------------------------------
\ pH | 6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 8.0
KH\ |
-----------------------------------------------------------
0.5 | 15 9.3 5.9 3.7 2.4 1.5 0.9 0.6 0.2
1.0 | 30 19 12 7 5 3 1.9 1.2 0.3
1.5 | 44 28 18 11 7 4 2.8 1.8 0.4
2.0 | 59 37 24 15 9 6 4 2.4 0.6
2.5 | 73 46 30 19 12 7 5 3 0.7
3.0 | 87 56 35 22 14 9 6 4 0.9
3.5 | 103 65 41 26 16 10 7 4 1.0
4.0 | 118 75 47 30 19 12 6 5 1.2
5.0 | 147 93 59 37 23 15 9 6 1.5
6.0 | 177 112 71 45 28 18 11 7 1.8
8.0 | 240 149 94 59 37 24 15 9 2.4
10 | 300 186 118 74 47 30 19 12 3
15 | 440 280 176 111 70 44 28 18 4
------------------------------------------------------------

If the chart layout is hard to see on this forum here is the original link: Determining CO2 levels by testing the pH and KH of your aquarium


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## Big Dog (May 17, 2010)

What time is it by you?


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## Doratus (Sep 14, 2010)

1535 hrs (3:35pm)


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## jrman83 (Jul 9, 2010)

Are you trying to figure out if you're getting at a certain CO2 level with a DIY system? You can gang mulitple bottles of your solution together to increase your bubble count. It may be possible to attain it on a 20g, but who knows how many you would need. I've seen the chart, but don't really care about it on my 29g planted tank. All I know is my plants are doing great and I'm only seeing about 4-6 bubbles per minute. But, the plants that are in there really don't "require" CO2. If yours do, then maybe you need to increase. If they are doing very well, maybe not.

I would suggest investing in a drop checker to test your CO2 levels.


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## NursePlaty (Feb 5, 2010)

*I have both the GH and KH API liquid test kit. The KH is very easy to use and the change in color is very noticeable and obvious. The GH however is impossible for me to differentiate. *


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