Hi John Rodrigues
Thats one simple old project which has not been conquered by anyone perfectly. I still dont see any reliable water level controllers or indicators used and adopted extensively. Its in my to do list.
The wired method of doing it is problematic. Wireless is the way to go. If you want to do it as a commercial product then go for long range communication devices like LoRa or Long range Zigbee. Because the devices can operate on battery and run for long time and the long range is necessary because these devices can be on single floor buildings as well as some one might want to use them for apartments which are quite tall these days and the signal from top floor or syntex tanks will not reach the ground floor, where normally the motors or the controlling circuit are present. Although it might find attractive , I would not use GSM devices for this application because GSM modules are power hungry and need a constant source of power to recharge their battery. They draw around 50mA current when in normal operation and 2A current when transmitting data and 1mA in sleep mode. Devices like LoRa can run in active or normal operation at less than 1mA and transmit at 25mA. There is no bootup time involved in LoRa or Zigbee devices. We can keep these devices powered off all the time and immediately turn them on send data and shut down. Its not the case with GSM module, they need atleast 45 seconds to boot up and acquire network. During this 45 seconds they consume lot of current. But still you can use them if you want to go for call based system.
And the detection method used for measuring the water level also makes a significant difference in power consumption.
There are lot of options,
Many people try to use conductivity method and fail because passing current through water will corrode the electrodes due to electrolysis.
There is ,
Capacitance method (high resolution),
Pressure method (I am designing something based on this). (High resolution)
Float switches. (Low resolution, Depends on number of switches used)
Float ball or Angle arm (High resolution, Limits the type of tanks to be supported)
Ultrasonic (High resolution, Unreliable)
I suggest you plan this based on the distance to be supported. Always choose the technology which will reduce the gap between your device and the user (Smartphone),
The shortest are ,
Things like Zigbee and LoRa need extra gateways.
Hope this answered the question :D
P.S : You can use Valtrack-V2 for this application. I have left a analog input in new version .