# Using 5 dKH solution in drop checker, comparing color to 4 dKH standard



## JustLikeAPill (Oct 9, 2006)

I just ordered the Cal Aqua "Pearl" drop checker. It comes with a 4 dKH reference solution that shows 30 ppm when green. It comes with a 4 dKH solution, but I also ordered a 5 dKH solution hat shows 38 ppm when green.

My question is, if the 5 dKH solution is the same color as the 4 dKH standard solution, is that registering 30 ppm or 38 ppm? Would I need a 5 dKH standard solution for them to match up?

Thanks!

PS: Here is the drop checker I ordered http://www.calaqualabs.com/Pearl.html


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## rjordan393 (Nov 23, 2012)

I would think so. The 5 dkh reference is calibrated to represent a higher level of CO2. Stick with the 4 dKH and the standard that they sent you. Contact the seller on how to use the 5 dKH. I suspect the standard would have to be different then the one used for the 4 dKH.


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## Yo-han (Oct 15, 2010)

I made a 5 dKH solution myself. It just shifts the color chart. All colors just have a slightly higher reading. So green is 38 instead of 30 with a 4dKH solution indeed.


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## rjordan393 (Nov 23, 2012)

I just checked the calaqualab site and they state their 4 dKH solution will represent 30 ppm when it turns green and their 5 dkh represents 38 ppm when it does the same. Actually both of these solutions are "Standards" and the "Reference" solution is what the standard is compare to, when the standard turns green.


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## JustLikeAPill (Oct 9, 2006)

Thanks for the clarification, guys! I appreciate it.


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