How much does it matter if u dont change the bulb

Is it really a big difference if u change the light bulb every 6 months or can it run for a longer time,and has anyone tested this.

well if you're talking about a 400watter or less, you want to change that. If it's a 1000 watts and you don't have money this time around for a new 100$ bulb, then you could run it again. The problem is lumens drop off, and if you want to grow pro, you need to max it out at 100,000 lumens per sq. meter. Most bulbs go to 10,000 hours I believe before rated lumens gets below 70%

depending on the hour rating on the bulb...it does lose intensity over its life...Copied from another site:

Effective working life: A lamp's intensity will diminish with use, and may also use more power. Note that MH lamps have a shorter effective working life than HPS. Also note that the capacitor in magnetic ballasts will deteriorate with use and consequently the light intensity will diminish. Ask the manufacturer for the useful working life of these items.

i havnt really tested this....but i know whne my bulb got older it lost alota lumens...when i put a new onne in it was like the sun again lol

When CMH first came out in 400 watt the companies called them ConstantColor and ColorMaster because the lights held spectrum so much longer than HID.
Cool I figured, so the first CMH in the budroom got used 5 years and still appeared better than the HID. In fact I liked it so much after 5 years I purchased 4 more M135 ballasts and CMH bulbs.
Holy shit! Not only did I take out the old bulb, I hit it with a hammer*. All the above posters are correct, about half the manufacturer's rated life and the bulb is done.

My sky blue HID is rated 5000 so it gets 2500 hours, at 84 hours/weeks we're talking 30 weeks. More than 6 months but not a lot more.
The CMH gives a good 10,000 hours, a full 2 years.
The cost still doesn't add up unless the initial spectrum is important. I can get a multi-vapor 400 watt for $14 locally. The 400 watt CMH is $121. Yes, the internet is cheaper, but the ratio is still the same. The CMH costs 5 times as much and only lasts 4 times longer. The major difference is multi-vapor has a higher green content.


*I hit it with the hammer carefully, wanted to test the innards and see if enough UVC comes out to sterilize my outdoor shed.

I change my 1000w's every 6 months. You can tell the bulb is junk when it gives off a white light, rather than the orangish colour they have when they're new.

Good question panta. I'm at the point that I question the legitimacy of everything a manufacturer says anymore.

i have done no test,but i change mine every 6 months.

I grew 5 harvests with my first bulb. Bulbs are expensive. Just trying to get the most out of my buck. I have grandkids to spoil so $100 for a new bulb is a major hit to my wallet.

thanks for the replies,il try my old bulb thats been running for 3-5months dont know exactly,and then il change them and see how much difference does it make in the same setup.

I ran a 400W HPS for a year. I use the cheap bulbs you can get at the local hardware store.
When I decided to replace it with a new one, I could tell a big difference. The bulbs lose lumens slowly over time that you will not notice it with your eyes. I have a cheap light meter and it shows a big difference between the new and old bulbs.
Keep a few old bulbs handy for an emergency. If you have a bulb failure, the old bulb will get you by until you get a new bulb.

That's good advice to keep the old one . I'm in the habit of throwing out stuff like that , in this case being that I can't run out and buy a replacement bulb anywhere nearby it's a good idea to keep the old one on hand. Could take 5-7 days for me to get another new bulb.