Sun Systems 2
Why is it like 5 bucks more for 150 more watts? And which one is better, sodium or halide? Thanks.

Don't know about the prices. But MH is better for veg. HPS is better for flower.

i should rephrase that. used individually throughout a plants entire life, in terms of quality and yield, how does an MH light compare with an HPS light

in terms of quality and yield? like the above poster said. Using both will get you the highest quality and yield. That said, some people use HPS throughout but the results are not as good. Simple solution to a first time grower is to get a switchable ballast that u can use both MH and HPS bulbs. Although, they do make some MH spectrum bulbs that can be used in HPS ballast. That could be confusing to someone who doesn't know much about them. This answer enough?