Components went together easily. Seems to sense water levels to specified accuracy. My only complaint is I need an on off switch as my application is not continuous.

This device works fine. Sometimes the measurement is very unstable (seems the case when the waterlevel in the tank is more then 1500 mm below the sensor). I tried to set the data filter upto level 4, but this helped not so much. I need to experience a bit more. Would be good to have the possibility to calculate/show/display the real volume (in m³ or Liter in stead of mm/cm) with a convertion factor in the settings. Could this be checked ?

The laser sensor is one of the more complex sensors of Ecowitt and it looks a bit fragile. I have the following concerns:

1) I am not sure about it's resistance against UV light [for all three components];

2) The connection between the battery house and the display unit is of white thin cable with identification as AWM 24AWG cable which I can trace as Copper Electric Speaker Wire Cable for Appliance Internal Wiring (see example). So it is an internal appliance cable, not really for permanent outside use, definitely not in the sun/UV

3) The eight 1.5V battery power supply is quite something. Ecowitt claims it is enough for a year when using the heater is switched on max 30 times a day. I will use it in a very moist environment (dew, mist, 1 meter above ditch water level etc...) so I have to see how this works out.

4) The whole device is specified as IP65 which means it can withstand rain but it should not be submerged [for longer periods]. This submerging may occur during heavy rainfall (in the eight years I live here it occurred once :D )

5) The laser will be of high maintenance concerning cleaning i.e. I assume weekly cleaning during spring/summer/autumn

All in all it looks like a fragile device, at least not robust enough for me. However given the rest of Ecowitts plastic stuff (I work with the WS80, WH40 and several T/H devices) I'll give this the benefit of the doubt but I assume it won't last long in the conditions I am going to put the laser to work (insects, rain, summer/winter etc...) and I will give it at most two years before I need another one (which now I am not sure I will buy as this won't be a necessity but a nice to have for me).

The LDS01 works basically (the proper air distance is shown on the LDS01 Display) and the HP2551 has found the LDS01 as well.
The depth value in the sensor settings on the HP2551 has been done and works, also the sensor name change has been applied sucessfully.

But there is one issue we have already written to the ecowitt support, waiting on their reply. The LDS01 and its values could be seen on the HP2551 sensor page but NOT on the main display page of the HP2551.

The FW of the HP2551 has been updated to the latest provided V2.03.

Waiting on the advise what needs to be done to see the LDS01 values on the main display page.

I had been needing a water level monitor for my home water tank but the options cost nearly a thousand dollars. This monitor is inexpensive and works well with my Ecowitt 2551 PWS. Simple to install and integrated easily into my current setup. Just needed to upgrade the PWS console firmware. Highly recommended.