I noticed yesterday that my algae blenny was a bit quite then last night and this morning he just seemed to be staying down int he same corner at the front of the tank. Even when I tapped the glass lightly he didn't move away. I have tested the water this morning and the results are: Ammonia - 0.25!, Nitrite - 0, Nitrate - 0, salinity - 0.023 and temperature 26. Other than the ammonia everything is as it normaly is, other than a water change is there anything else I can do? does this mean that something has died in my tank somewhere? The other fish and shrimp seem fine.