Should i replace the bulb?

[Iammygod]

Hi.

my lux meter measures 60k lux from a 600watt MH bulb in the center of the canopy and 20-30k lux at the corners of the 3.0×3.0ft area; the protection glass between bulb and canopy has been removed. Should i buy a bulb or not. It has been +2k hours in operation.

[HappyDaze]

Depends on the bulb....Hortilux says you can get 4000 + hours out their bulbs with a 5% drop in output. Your plants looks great and it looks like you have good coverage, why change?

[Iammygod]

4k hours for an MH Bulb? Do you sure?

[oldjarhead100]

Lux meters are for hps bulbs .they will give you an idea about distance with a MH ,there is a formula but I cant remember it ,ask Nebula about it , I use a light mover so I can go a little closer than a fixed position light with out burning the girls , Whats with the paper or cloth hanging from the light , doing it like that causes 2 things that I can think of ,it decreases the light volume at the edges of your girls so you will have light fluffy buds,and second is that stuff flammable cause thats a good way to start a fire those bulbs put out so much more heat than a reg. house hold light bulb , If you think they help alot then take 2 down and leave 2 up see what has bigger and harder buds . never stop with the ideas though , I am constantly putting stuff out there to see if others have tried it , some good ideas some not so good lol we are here to help, this is the best dam forum out there

[Iammygod]

What formula? A correction coefficient?

We know that MH has highter blue/red ratio than HPS Bulb and blue carries more energy than red. So MH produces less photons than the same wattage of a HPS; less photons but more energetic ones. I recall every 10.76 lomen of MH and HPS contain 0.15 and 0.13 umol PAR. Have you been talking about a 15/13 correction coefficient or something?

Those papers are doing well... absolutely well. I took 9 point in a 3×3 matrix at the canopy height and measured light level. Those papers increase average light level by 7% with almost no changes in leaf surface temperature of them. Corners show 15% increase

My cooling system is also working excellently. It is super efficient and most silent one in the world.

My lux meter is the one that Nebula has suggested. So i thought maybe i can find someone to compare my light with his or her one.

I measure 60k lux radiation at 45cm from the 600watt MH bulb.

[oldjarhead100]

I just relayed what I was told when I switched from an hps to MH sounds like you know more about it than I do , so what kind of cooling system do you have sounds interesting , I have the same meter what did you want to compare ,does your light have one or two bulbs , so what made you think of those papers ,sounds like you did your research , I have to convert cm to inches but I will take a reading today ,I am planing on shutting down until Aug 15th when this run is done . Tammygod when I post I try and give ideas unless I know an answer to a problem , some of them are good some are not lol . I find there are usually 6 ways to get the same thing done ,I did not post a formula because I didn't remember it , it was pretty confusing . If I offended you with my post I apologize that was not my intent after rereading it maybe I should of suggested rather than state , I generally dont say statements like that , Im more of a in my experience kind of guy lol

[Iammygod]

Oh man. You were right. Those papers increase avragw light level which sounds good. The problem is that they are focusing light toward the center. The plants show some kind of light stress after ive change the sky for 3 days.

[Toker1]

I have never heard light meters can’t read MH before. I thought that was only true of LED? No?
Anyway, your bulb is rated in lumens, not lux (which is dependent on square area). You need to solve the conversion first, then compare the drop to the manufacturer’s rating. Anything at or over 10% in light losses is a trigger to replace the bulb (if you care about maximizing efficiency).

[kingfish]

I keep my canopy between 57K and 60K lux. I use 1000w HPS.

[oldjarhead100]

kingfish why do you keep your canopy between 57 and 60 k I always thought it was better to keep it closer to 85 k,

[kingfish]

The maximum lux for flowering pot is 45K-70k lux. Anything above that is wasted. Albeit there are some strains that may require more. But I have been satisfied with 57k-60K. through out all my grows. I measure it at the top of the plants.