KH is 8 in Filtered Water. Is this ok?

[LeanneP]

I have just checked my tap water and it is at 7 and the filtered water is at 8 so I guess the filter is affecting the hardness some. It doesn't say what kind of filter it is, just that it takes out minerals, heavy metals, contaminants, chlorine etc. It is for aquariums specifically so I would hope it wouldn't screw up the water. I just thought I read somewhere that R/O water had 0 for KH so I was wondering if that was making my KH higher since it was already at 8 when I added salt to it.
Leanne P

Originally Posted by 425nm

Is this cartridge filter a carbon filter? If it doesn't have a deionization resin it probably won't affect hardness.
Is that water hardness reading the same as your unfiltered tap water?