Hps kicks out about a 1/3rd more lumen than MH. bulbs and ballast are inrelavent
So maybe the LED does more than hps?
Lumans are for humans (the light we see with our eyes)
PAR is for plants (photosynthetic active radiation, the light plants see)
Long story short, don't listen to anything about lumens when it comes to growing plants. You need to figure out how much PAR is being produced by the light, and how much of that can actually make it to the plant.
Side note: HPS and MH for example can give off a shitload of PAR directly next to the bulb, but since they also produce a ton of heat you need to keep the lights farther away from the plants, and because of the extra distance between the plants and the bulb a lot of the photons of light (or PAR) get lost in thin air and don't make it to the plant. Think of all that wasted electricity turned into heat and lost photons every minute the light is running.
Another thing you can't really use by itself to know if a light fixture is good is how much wattage of electricity the light fixture actually uses, it only matters how much of that electricity the drivers and LED chips are converting into photons of light that the plant can use (or PAR, or photosynthetic active radiation), and not being lost to heat (can be calculated as heat watts).
This is what really affects especially the LED grow light market, why some LED lights (even expensive ones) produce shitty results, while others produce good results. The question that should come to mind now is
How do I know if the LED light fixture I am looking at is a good one? Answer:You need to know how efficient it is, or rather, how much PAR (or PAR watts) it produces per wattage of electricity that it uses from the wall.
LED chips are becoming more efficient as manufacturing is being continually improved upon by large reputable companies like CREE and Philips and CREE even publishes the data that shows that efficiency of (their) LED chips improves if you underpower them (run them soft, or lower current than their rated maximum). Also LED chips like computer processors and tv screens they don't all come out of the factory the same quality, the good chips are more efficient and tagged as high bin or good quality and the not so good ones are marked a lower bin and used for other purposes.
Simply broken down the Quality of LED chips/drivers and how much current the drivers run through the LEDs ultimately determines how efficient a LED fixture will be. The only ways I know of to get a good efficient LED fixture is:
- Get a PAR meter and test it
- Find out exactly what parts are in the fixture and research to see if they are good quality and paired efficiently.
- Do the research on these forums to learn how to build your own high(er) efficiency LED fixture.
Some food for thought:
- Are there companies that make good quality LED fixtures and charge a big markup? Yes
- Are there companies that make good quality LED fixtures and charge reasonable prices? Yes
- Are there companies that make shit LED fixtures and charge way too much for them? Yes
- Are there companies that make shit LED fixtures and charge low prices? Yes
- Are you taking a gamble if you don't follow one of the above methods to picking an LED grow light? Yes
- Can you learn how to make your own high quality LED light and save money? Yes!
In closing, these questions I ask myself when thinking about buying an LED light:
- Considering good LEDs are supposed to last 10 years am I comfortable potentially paying a lot of money for a light that might be made of crappy parts or not designed to run efficiently: no
- Am I willing to invest my time to learn about LED lighting, especially considering in my opinion it will probably replace all other forms of artificial lighting and by doing so I can save money for any and all lighting I would need in the future: hell yes
- Is RUI an amazing place to learn about all of this stuff from the many people that have contributed many hours and $$s to understand it better: you better fuckin believe it!
