The temperature is rising rapidly, but the water chemistry is still looking fairly good. Phosphate, nitrate and nitrite are undetectable; we have a very small amount of ammonia (0.03 mg/L, pH 8.5), but this may just be a temporary fluctuation, and it is not so high that it is a concern.

The water temperature is currently 16.4 °C which is about 3 °C higher than this time last year. Oxygen levels are high (10.7 mg/L and 110 % sat.) at the moment due to the growth of plants and algae. With the rising temperatures and growing algae it is possible that oxygen levels can drop at night, so, as a precaution, we will start to run the aerators more often to help reduce the chances of fish stress, especially at night.

If you’ve visited Darlow over the last month you will have noticed that the water is a little cloudy, but nowhere near the high turbidity we saw last year. The water temperature is also now too high for the algae (Dinobryon sp.) that caused the fish deaths last year, so we are unlikely to face the same problem this season. With the rising temperatures we have restarted clearing the Argulus posts as this may help to reduce the numbers of this fish parasite and reduce the chance of fish stress as we move in to summer.

Categories: Environment