m0useanswered grow question a year ago Good advice below regarding Photone app. however it is not accurate with out calibration. so use it with that in mind, It will be stable and consistent in its reading on the device it is installed on and just that device, but its not a real or accurate PPFD measurement, it can get fairly close when calibrated but you need a good tool to do that. It is using a fancy equation to covert Lux to PPF and DLI.
For the real readout that not calculated you need a quantum senor and they are not cheep.
I would use the light in its max setting with bloom and grow enabled. That style of light is not pulling 1000W from the wall. its a theoretical amount of watts the LED didoes can handle but they are never ran at 100% as they would burn out to fast. That light might be pulling 100-150W in reality. Its shit marketing when they do that.
If the plants are not getting burned and you have nice internode spacing keep it at the height its at and use LST and HST to control the height of the plant. obviously move light closer if node spacing is stretched to much. and away if its to cramped.
Good Luck!