That time.

[morgan175]

I have an orbit lighting fixture with 2 double ended halide lights. What should I replace them with. I mean the brand and I really don't want to spend the bank and what is your favorite K.
I also don't understand y lighting makes algae grow. How often should I replace these bulbs? If you replace them twice a year that is 2oo. Just seems high.

 

[snakeblitz33]

The older the bulbs, the more the spectrum shifts from white/blue to red. Red light makes algae grow because that is the spectrum that it loves the most.
Ushio, Phoenix, XM, Radion, ... all good brands of metal halides. Not sure if they all make double ended bulbs. You probably shouldn't pay less than $40 a bulb .... preferably $50.
These bulbs should be replaced at minimum once a year.

 

[morgan175]

I was going to pay less now I won't thanks.