Did the first accurate measurement of Ammonia myself and found that Ammonia is < 0.01mg/l, Nitrite is 0.20mg/l and Nitrate is 10mg/l. Since the Alkalinity dropped severely to 5.0 dKH, I decided to open up the tank so that evaporation is increased. In one hour the topup pump came on about 6 times. Since this was quite severe I closed down the lids of the aquarium.