I live in a suburb of the city. It’s still very busy and right next to the airport.Now I will learn you a new thing. When you start with a brand new probe - my experiences is that it is rather unstable the first weeks and the probe many times needs to be recalibrated after 2 - 3 weeks. Before you do anything else - recalibrate the probe. After that you know that you can rely on the readings.
The rise of the pH when you two was away correspond to the same rise (of around 0.1 - 0.2) of average pH when me and my wife is away. But your rise of 0.2 unit indicate that you have more gas exchanging through your open water surface compared with the skimmer. When I changed to outdoor air - the normal dip if we are at home is around 0.1.
Where do you live – in a city or at the countryside?
Sincerely Lasse
