I set up a new tank that will be a mix reef. My alkalinity has been in the range of 8-8.5 dkh reading from the Apex Trident. I was told to try to keep DKH at a level of 9. It seems that if I dose and raise my levels to 9 the next day they're back down to 8.5. If I don't dose anything they pretty much stay at 8.5. Should i be seeking the numbers or just let it stay at 8.5? Right now I don't have and corals in the tank.