How often Changing High pressure sodium lights

How often are we suppose to change the 1000 watt HPS lights?

I heard from a friend you're suppose to change it every 4 months because the lights get dimmer after prolong use and so its better for the growth of the plants. Is there any truth to this?


18/6 & 12/12 cycles.

Its recommended to change it every year however I have seen people use them for multiple years. Its up to you. I personally don't plan on changing mine til it burns out.

If you look on the box a light comes in, will tell you the initial lumens. To answer your question, yes they do lose lumens over time. This next paragraph is quoted from my National Garden Wholesale catalog.

Most lamp manufacturers also rate their lamps by "average life hours" and usually claim 10,000 to 24,000 hours. These ratings are based on when the bulb will completely fail to come on. They do not factor in loss of intensity or loss of color. HID lamps lose intensity and color through normal use. This is ok if you are lighting a warehouse, but when it comes to plant growth, these losses can mean wasted electricity and poor plant performance. Serious horticulturists recommend that you replace your lamps after 6000 hours of use. This equates to using your light 16 hours a day for one year.

I'm not saying that I do or don't believe this completely, but I'm not going to push my bulbs past 7000 hours.

10 to 12 months or 5000 hours. Anymore you are begining to lose streangth. HTH!

just over a year,

Anytime you "sell" a bud to a buddy for $$$$$ because his plants all turned hermie.

Every year... Pretty simple stuff.