MH Bulb Questions

[StirCrazy]

I personaly think the yearly changing bulbs sugestion is a myth started by fish stores to increas sales on consumables. the best indacater is a light meter but you would have to have that from day 1 for a comparason.

here is my rational on this.

an average MH bulb has a rated life of 8800 hours or higher (this translates to 2.4 years at 10 hours a day) and at this life span most only have a output drop of 30% (some lower some higher) but 80% of this drop is with in the first 1.5 years. so after 1.5 years your intensity has dropped up to 25% but the bulb is still working good and will only drop another 5% over then next year. I know from my testing after 2 years my AB still puts out more PAR than all the new SA bulbs I got to test so should I change it out just because some one said after 1 year to change it?

Also ther eis the 6 month VHO recomendation, well mine is going on two years and looks almost like it needs changing but that was only in the last 3 months, also remember I was overdriving my VHO by 15% . I think on a workhorse or comprable electronic ballast there is no reason a VHO shouldent last 1.5 to 2 years.

so to answer your questing should you change it after 1 year.... well do you want to change it? it sounds like you do.. and if you desire a more whiter look then by all means change it. maybe spend 30 bucks on a little lux meter at the same time and do a measurment from 12" away.. then do the same measurment every month to see the drop. you will fine that the major part of the output decrease happens in the first 6 months and then the rate that it drops slows down.

Steve