Bulb changing

If this has been asked before on here I'm sorry for asking again, but I can't find it :o

I have been growing now for around six years and in all that time I have never changed the bulbs for new ones. I am using a 400 watt system and I use a metal Halide bulb for the vegative growing and switch to a high pressure sodium for inducing flowering.
Now in all this time I have had rather good results and some decent crops, however the last crop was totally wiped out I suspect due to a blight of some kind, but I have noticed also the last few crops have been declining in there yeild and the plants have be getting a little on the slow to grow and puny side. Well I an not sure if it's the seeds or something else causing this?

The question I would like to ask is do the types of bulbs I am using require replacing at certain intervals, do they start to deliver less of the correct spectum of light with being used for so long?

I have tried everything to put things right, the only thing I have not done is change the bulbs, thats why I am asking this question.

Thankyou guys ..........................love mand xxx :)

your ment to change the bulb ever 9 to 14 mounths

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Originally Posted by greendevil

your ment to change the bulb ever 9 to 14 mounths

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Thanks darling, I reckon mines a bit over due then...............I get a couple of new ones straight away ;)


love mand xxx :)

make sure when you're putting them in you use a shammy or a dry soft cloth to hold the bulb.. your fingerprints will reduce the life of the bulb... the old one wouldn't matter

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Originally Posted by BobBong

make sure when you're putting them in you use a shammy or a dry soft cloth to hold the bulb.. your fingerprints will reduce the life of the bulb... the old one wouldn't matter

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Thankyou Bob, I never realised they were so sensitive.

Much appreciated :) .......................love mand xxx

well that answered your question.

You will see black around the base of the bulb that is a good sign of when to change it. Not because it is going to go out right away but you are loosing lumens.

Yea...these bulbs will actually degenerate over time even WITHOUT bing used.

Two to three grows I think is the ideal life time.

Thanks alot all you guys, I think I've had my money's worth after 6 years then :)
Already priced a couple of new one's up and I'll go and pick them up in the morning.

Thanks everyone :) ...................love mand xxx