As long as 7.8 isn't the highest reading that your test kit can register, you are ok at 7.8. But, if it goes any higher, you'll want to lower it. (To clarify -- you have a K-2006 kit so your kit can read higher than 7.8, so you know that it actually is 7.8. However, if someone has a kit that can't read past 7.8, when they get a reading of 7.8, that means it could actually be higher than that but the kit can't distinguish anything higher. Make sense?)