[panther685]

I just purchased a drop checker from ebay and the instructions are not clear.

What water do you put in it? from the tap or aquarium?

The instructions say to put 7 drops of solution and to add 5ml from the jar. What the heck is the jar?

 

[Left C]

The directions that come with most drop checkers are wrong.

You don't use aquarium water or tap water. They will give you false readings.

Along with the indicator solution, you add a known 4 dKH carbonate based solution. This allows the drop checker to function properly and it follows the CO2/pH/KH relationship.

SuMo has some 30 ppm solutions. That is the 4 dKH solution.
http://www.sumoregulator.com/DropCheckerSolutions.html

GLA has some 4 dKH solutions.
http://www.greenleafaquariums.com/co2-drop-checkers.html

You can also make your own.
http://www.plantedtank.net/forums/general-planted-tank-discussion/42429-kh-standard-how.html

 

[DUHK]

Thanks LeftC. I was also confused since they claim that it comes with the drop check solution.

For the SUMO drop checker solution, do you have to email them to get more information to buy it? Because I don't see a buy link anywhere.

 

[Darkblade48]

Thanks LeftC. I was also confused since they claim that it comes with the drop check solution.

The solution that comes with the drop checker is most likely the bromothymol blue pH indicator reagent that is required in conjunction with the 4 dkH reference solution.

 

[Left C]

Thanks Left C. I was also confused since they claim that it comes with the drop check solution.

I know. It catches most people.

I believe that it was Hoppy that came up with the idea to use known dKH solutions. Finally, 4 dKH was chosen because when it turns green, it represents ~ 30 ppm of CO2.

For the SUMO drop checker solution, do you have to email them to get more information to buy it? Because I don't see a buy link anywhere.

Go here: http://www.sumoregulator.com/Contact.html

Then you will see where to place orders. It reads:
[email protected] <[email protected]>

I believe that their dKH solutions already have the Bromothymol blue pH indicator solution mixed in. The 30 ppm product is the one that is 4 dKH.

 

[Darkblade48]

I believe that it was Hoppy was the one that came up with the idea to use known dKH solutions. Finally, 4 dKH was chosen because when it turns green, it represents ~ 30 ppm of CO2.

On another note, I thought it was Tom Barr that touted the use of a reference dkH solution in a drop checker.

 

[Left C]

On another note, I thought it was Tom Barr that touted the use of a reference dkH solution in a drop checker.

To the best of my knowledge, it was Hoppy that thought of using the right solution in them and then he, Tom and a few others worked it all out.

Drop checkers have been out for many years, but until Hoppy thought of using the pH/KH/CO2 relationship correctly inside those drop checkers did it work out. Also, the Bromothymol blue solution is sensitive to CO2. This was key in their pH indicator solution search.

I have 2 Sera drop checkers that are over 10 years old. Their directions say to use aquarium water and the freshwater low range pH indicator solution in them.