I see people here likes discussions about light sources and i want to show you something i found.
It is as economic as bigger LEDs and T5HO and gives up to 10 times more light than an incandescent bulb.
Im talking about Xenon light bulbs ,the types used for cars.
They are really expensive but from China as a kit they are quite cheap.
A 30 watts xenon HID can give @3700 lumens wich its the equivalent of 400 watts incandescent.
So far this is the best light i have found and i plan to use it for somme of my grow lamps.
It looks like an incandescent ,flickers like a T5 ( only at the beginning until it gets hot) and consumes electric power as little as LEDs.
Here is a lamp i build where the 2 bulbs are Xenon HIDs and in the back theres the computer power source ( they work at 12 V).Used this lamp to grow corals.
But I don't like their color to be honest. The (high quality) LEDs I have produce better light and are more efficient. But in price a LED can't match a HID lamp.
What you dont like about color of HIDs?
They are.being sold in manny colors and more diverse than the white Leds .
For instance white leds are sold as cold white or warm white ( yellowish) but the HIDs have probably 7 types of white from yellowish to more and more blue.
HIDs are as efficient as LEDs .The big Leds that need a heat sink are not that efficient as the small plastic led diodes( the lamp in picture also has 1200 small,most efficient type of leds) and only those small leds could beat HIDs at efficiency and they also beat the bigger leds but when people talks about led lighting they are talking about what every house uses,inneficient big leds.
My experience is based of a sample size of 1. That lamp doesn't provide useable colors accuracy (as seen with the eyes of a photographer).
The LED I am using as a reference is a COB led (1cm²) mounted to a massive heat sink and ran at 1/3 its rated power from a constant current supply connected to a 48V grid. The Color Rendering Index might be 85. And now one can get LEDs with a CRI of 95.
For "normal use" HIDs are completely fine (and can provide a brightness that is not easy to archive with LEDs without a dedicated cooling solution – I will probably use water to cool my next installation).