TL;DR: I need to raise my KH a few degrees. I took some dead Celestial Pearl Danio back to the shop and they tested my water and everything was fine but KH was 1. They said that could have been stressing them out too much because of low ph stability. This might account for my RCS failing to moult occasionally. Does bogwood lower KH as well as PH? How can I raise it safely and foolproof?