I dont understand how to measure KH wiht my new Hagen Test Kit???

I think (I'm not at home, so I don't have the kit in front of me) that what that means is that you have 20 degrees of Carbonate Hardness in your water. That's pretty low, from what I've tested in our own tap water in Dallas.

Instead of putting 5mls in the tube, to be more accurate, put 10mls in the tube. The add a drop. Shake lightly. If it doesn't change color add another and so on until it changes color. If it takes 5 drops you then have a kH of 2.5. If it takes 10 drops you have a kH of 5. By doubling your test tube water you are getting a more fine reading. I don't worry much about that multiplying stuff. Most people refer to their kH in terms of "kH 3" or "kH 4.5" or whatever. Keep it simple.
Getting the more accurate reading gives a better idea how much CO2ppm you've got when you compare your numbers on the chart.
Len

That's why I like Len....

HE AM SMART!

The hagen test kit measures in ppm not degrees. My water took 9 drops so I have a kh of 90ppm or 5 degrees. Tim

No, you have a kh of 20 ppm. I think it says on the box to multiply by.056 for degrees. So you have 1.12 d/kh. VERY VERY SOFT. I wouldn't add the co2 until you get the kh up some. Try a teaspoon of baking soda. Wait a couple of hours and test again. Try to get up to 6 drops. That will give you a kh of just over 3 d/kh. Don't count the very first drop you put in. That should change the water blue. Then start counting until the water turns yellow.