What would make ph act like this?

[Chiroptera]

I went to test my water today and when I had done all my other levels and held up the vial to the color chart, it was a color I'd never seen before - blue. It looked a little less than the 7.8 mark.

Last week, it was 6.

The first vial is the tank water. The second is from the bathroom sink, third from bathtub, fourth from kitchen sink. All read 6.4, always have. So in a tank with a pH of 6, and tap water that's 6.4, how does the pH spike to nearly 7.8?

I tested the tank water two more times, in case I got the vials messed up or something didn't work, and got an identical blue color.

The substrate hasn't changed, all the plants are fake, the only thing I added was a pleco and a piece of driftwood, which should have the complete opposite effect! I just don't understand. Does anyone have a similar experience to share? I'm doing a 60% water change tomorrow because my NitrAtes were about 60ppm, and I want to see if I can correct this issue. I'm going to test the PH before, directly after, and once a day after the water change and see if it changes in that time span.

Extra info:
Ammonia- 0
Nitrite- 0
Tank size- 10 gal nursery tank
Filter- QuietFlow 10

 

[Andy Sager]

Higher oxygen levels will cause PH to rise. If you've added an air stone or some other calcium based decoration, the ph will rise. If you've increased the airflow to an existing airstone, this too could cause that.

Hope this helps.

 

[Chiroptera]

Higher oxygen levels will cause PH to rise. If you've added an air stone or some other calcium based decoration, the ph will rise. If you've increased the airflow to an existing airstone, this too could cause that.

Hope this helps.

I raised the water level so the filter output blows directly into the water, which seems to have increased the bubbles in the water, that would be possible.

 

[Andy Sager]

I raised the water level so the filter output blows directly into the water, which seems to have increased the bubbles in the water, that would be possible.

In an experiment with a new area we had started importing fish from, we had lowered the PH of the water in the containers that the fish were going to be acclimated in. When my workers forgot to lower the volume to the airstones, all 12 containers had high ph again. Nothing else but this could have caused this change. You probably had a similar situation happen when you changed the water level.
Hopefully this solved the mystery