Can't keep dKH high..

It keeps falling, I add some superbuffer to it and its at 9.5 for a day or two, then drops back to 7 again.. It's getting rather annoying haha..

Any body have any idea why if would keep going so low?

Thanks!

Also, in order to avoid opening a brand new thread..

Anyone have suggestions for a fish to add to my 46 bow reef tank? I have two clowns in there now and I'm starting to think about adding something.

Thanks again! lol