i plan on buying a 2 bulb 500 watt MH light fixture with 2 fans and mounting legs. It has a 15,000k bulb and a 20,000k bulb both double ended, i was wondering how long it would last i have heard 2-4 months 6-9 months and a year.:1zhelp: 55 gallon tank long.
DE MH 20,000k Bulb How long....
- Thread starter Jack1243
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The Kelvin rating doesnt affect the life of the bulb JFYI.
Its the length of time the bulbs are on for. In an avergae 8 to 10 houra a day of the bulbs being on, anywhere betwen 9 to 12 months.
It is hard to tell a difference since the bulbs light ouput will be less. Since you see the tank everyday you wont be able to tell when this happens. You dont want your corals to let you know this is happening either.
Not only can your corals start to not look so hot, algae can come into play.
Its best to replace them every 9 months or so, to avoid those occurances. When you are going to replace them, do one bulb at a time about a weeks difference from eachother.. This will allow you to not shock the corals.
The bulbs and ballast will be marked as to how many watts they are (and the wattage also needs to match). I've not heard of 500w MH ballasts and bulbs for the hobby (at least not in the US), so it's more likely that it is two 250w bulbs and two 250w ballasts (or a dual 250w ballast).
MH bulbs tend to last 6 - 9 months. I've never heard of anyone replacing them every 2 - 4 months -- I find it hard to believe that MH lighting would be as popular as it is if bulbs truly needed replacement that frequently. The cost of replacing every bulbs every 2 - 4 months would be tremendous over the life of the hobby. I have heard of people running MH bulbs for as long as 12 months, but they typically admit noticing a decline in coral appearance and growth.
MH bulbs tend to last 6 - 9 months. I've never heard of anyone replacing them every 2 - 4 months -- I find it hard to believe that MH lighting would be as popular as it is if bulbs truly needed replacement that frequently. The cost of replacing every bulbs every 2 - 4 months would be tremendous over the life of the hobby. I have heard of people running MH bulbs for as long as 12 months, but they typically admit noticing a decline in coral appearance and growth.