I just made a batch last week. I added buffer (Seachem reef builder) I just happened to have an old bottle of this on my fish supply shelf. I haven't tested the water yet. But, tomorrow it will be exactly 1 week since i mixed it. I try to do my water changes on Thursday or Friday. I'll test it then. Hopefully, the @fishdoctor is right about just adding buffer to keep the alk stable.