This tank has been running for over a year. I have never had low KH and havnt had detectable nitrates since its cycle? I did a store bought water change (5g on a 29g bio) a couple days ago and the next day bought an anemone the next day. Past 2 days the anemone hasnt looked very good so I just checked the water and KH was low (some where around 80) PH was way low (7.5ish) and there was slightly detectable nitrates. Could this be the water that I bought or is the anemone dead and its messing the water up? Everyone else seems fine, mandrin is swiming around as usual, clowns keep flirting with eachother. Any ideas? I added some PH buffer to bring the PH back up ( I tend to have to do this for some reason I cant keep a stable PH)