high pressure sodium lights

Why use them? Are they better in certain stage of the plant?

No single light can compare to hps during flowering, imo. Plus, try to get 50,000 lumens from cfl's...

yeah a 600 hps puts out around 100,000 lumens, i grow with hps full cycle and it works killer

HPS is the proper spectrum for flowering is one reason, another is that it's the most efficient giving the most lumens per watt of any other option.

So just for flowering, or for the whole growth? You confused me a bit.

either, both

U can use hps the whole way.

The reasons are color spectrum as well as light penetration,color spectrum can be matched using other forms of lighting but penetration & intensitity cant be matched by any other form of lighting.

The standard & most effective forms of lighting for growing marijuana indoors are High Pressure Sodium(HPS) & Metal halide(MH),the color spectrum of HPS closely resembles the color of the sun in the fall when plants are bearing fruit,the color spectrum of MH closely resembles the color of the sun in the spring when plants are sprouting & building their plant mass.

Some growers use MH lighting for the vegatitive stage then switch to HPS durring the flowering stage for maximum performance,If one form of lighting must be chosen for an entire grow then HPS is the better choice over MH,mainly due to the added lumen output with HPS but both MH & HPS will work for the entire grow.

Interesting.