The drop in sensor detects the pressure at the bottom of the container and converts that to a signal. The one I have has a range of 0-5m which is a bit too much. I have seen on Aliexpress similar ones with a 1m range which should be more accurate. This is the link to the PiHut one I have. PiHut Sensor
How have you mounted the sensor gy5000? Is it in the liquid?
No. My tank has a tap at the bottom which I screw it into. FYI. I didnt know if a pressure transducer would work for such a small head of fluid but it does.
Thanks. I wonder if that type of transducer would work by placing the transducer above the container and using a tube going down to the bottom of the container. I would have thought that the sensor would read the volume pressure rather than external pressure as long as the tube was sealed to the transducer.
I think this is rapidly falling into a “ not worth the hassle “ project .
Just park the container where you can see it out of the window or put a camera looking at it
A head of 50cm would produce a presure of;
- 4.91 kPa
- 0.71 psi
- 0.0491 bar
Tom.... 
Hi,
I don't know if it's already been mentioned, I just skimmed the thread.
But if it is a plastic tank, you can have a look at the FDC2112 from TI.