drop checker question

[timwag2001]

ok i picked up this cheap drop checker thing from red sea. it says to add 2 drops of the co2 indicator with 1 ml of aquarium water. i've heard that you should use distilled water with in a drop checker. is that correct and what do i use with this?

 

[NeonFlux]

You can use tap water

 

[timwag2001]

but not aquarium water like the instructions say?

 

[Dr. Awkward]

X2. I have that same drop checker and I found out you need to use either tap or water from a tank with normal parameters. If you use water from a tank with a really low hardness the liquid stays yellow even if you stick it in a second tank with no CO2.

 

[coach_z]

4dkh water is ideal (aka 4 degrees of carbonate hardness i believe)

 

[KarlTh]

Totally useless unless you use 4dKH made up from distilled water. Might as well just do a pH test otherwise.

 

[James0816]

4dkh water is ideal (aka 4 degrees of carbonate hardness i believe)

Yep...distilled water and baking soda. There's a recipe for the mixture around here somewhere. I made up a gallon of it some time ago.

* EDIT *

Found my notes:

To make a KH standard using baking soda you would need the following.
· distilled water
· baking soda (new and unopened would be best)
· .01 gram scale (a calibration weight)
· 500 ml graduated cylinder
· 50 ml graduated cylinder
1. Measure 3000 ml of distilled water using the 500 ml graduated cylinder and put it in a clean container. The container could be an empty 1 gallon distilled water bottle. (I found it easier to use 3000 ml, instead of the often suggested 5000 ml because you can make your standard with 1 gallon of distilled water instead of having to have a larger container or multiple containers)

To read the precise water level in the graduated cylinder.

-Place the cylinder on a flat surface.
-Make sure your eye is on a level plane with the of the meniscus.
-The meniscus is the half-moon curve formed at the surface of liquid.
-Water should be read from the bottom of the meniscus

2. Weigh 3.60 grams of baking soda, add it to the 3000 ml of distilled water and mix well, this will make a 40 dKH / KH standard.

3. Pour 450 ml of distilled water into the 500 ml graduated cylinder.

4. Pour 50 ml of the 40 dKH standard into the 50 ml graduated cylinder

5. Pour the 50 ml of 40 dKH standard into the 500 ml graduated cylinder and mix well, this will give you 500 ml of a 4 dKH standard.

 

[Squawkbert]

^ this is an approximation only (given the lack of compensation for moisture in the baking soda and that you can't just "cook out" any water that's in it...). If you use this approach, you should also use a kh test kit to make sure you're in the correct ballpark.

Here's a reasonably priced alternative: http://liquidarthome.net/khstandard (oops - it seems GLA has purchased this product line - new link: http://www.greenleafaquariums.com/co2-drop-checkers/kh-standard.html )

 

[timwag2001]

thanks for the info everyone.


soo why is it that 4 dkh soultion is accurate? what if my tank water is less than 4dkh or more than 4 dkh? just curious why it has to be like that

 

[jpappy789]

Gives you the green color for 30 ppm CO2, which seems to be the recommended amount now. A lower dkh would show up yellow I believe.