Changes in soil moisture

Ranjo

I've built a home-made soil moisture solution and would love some help on the results I'm seeing. I'm a very minor garden enthusiast, but know nothing really!

The plant is a ginseng ficus, purchased in IKEA. It's pot does not have holes in the bottom. It's sitting on a window sill, getting the morning sun. The soil moisture sensor is stuck in about 1-2 inches at the top. I'm staking readings every 15 minutes, as well as inside/outside temperature & humidity readings.

Here are my questions, would love any help on why the soil moisture measurements act this way.

The moisture reading goes up and down during the day. The room is centrally heated. Does the moisture rise to the top of the pot when the temperature (or maybe humidity) is changing?
After watering, the moisture reading stays quite steady then starts to fall and drops quicker and quicker. What I notice is the soil moisture readings become much more erratic. Is there a known reason for that?

thank you for any pointers!

Reckless Abandonment

What type of moisture sensor are you using. When you say moisture levels going up and down could down to many factors. Quality of sensor, sunlight, length of time heating is on. Are you watering at the same time of day or just when the plant needs it ?

Ranjo

The sensor is the one at the link below. I don't water the plant daily, just when the moisture level reaches a certain threshold.

https://www.seeedstudio.com/Grove-Moisture-Sensor.html

Turbulent Bill

Try running the sensor in ambient air instead, and then maybe dipped in water. Will let you isolate if it's just a measurement issue, or if the readings look legitimate.