Got my water test kit in today.
ph 7.5
ammonia .10
Nitrite 0
Phosphate 0
First, let me apologize for my perceived inexperience. I certainly do not mean to overstep any boundaries. I am just trying to help.
I am going to assume you used the API Freshwater Test Kit another member linked. That means your ammonia is 0.1ppm (mg/L). If my lake tested that, I would be alarmed. It is mitigated somewhat by your pH but interpreting ammonia readings is also temperature dependent. Can you measure the temperature?
Ammonia exists in two forms in the water, NH3(unionized ammonia) and NH4+(ionized ammonia). NH3 is toxic to fish at >0.03 mg/L (ppm). NH4 is relatively harmless. The ratio of concentration of each is pH and temperature dependent. The higher the pH and or temperature, the more of the NH3 will be present.
Now that you have a test kit, perhaps taking measurements at various points of the day may show a rising pH and temperature at a certain time of day, thus raising your NH3 to dangerous levels for short periods?
