How often do I change bulbs?

[Sealtagger]

I'm sure this question must get asked all the time by newbies (me), but couldn't find topic here or get archives to work.

I had a nice discussion yesterday with another member that said I should replace VHO lighting about every 6 months and MH about every 12 months. I have purchased an older system from someone else and was going to wait for the bulbs to burnout before replacing them.

Are there standards for bulb replacement? I realize the answer may depend on the type of tank setup and type of critters being raised.

Thanks, Dave

 

[bryan1560]

The rule of thumb is to replace MH every 12 months. but be carfule when you install new bulbs, you may want to reduce the length of time they are on in the begining. The bulbs will have a stonger spectrum and you want the fish to get used to the new high intesity. You don't want you fish to get sun burnt...LOL...

If you wait for the bulbs to burn out you will be starving your marine life of vital none visible light. Your corals will eventually die and your fish will begin to resemble a scrawny paste white kid from North Dakota mid December.
Bryan

 

[Sealtagger]

Thanks Bryan - Now that brings up another question. How long do people cycle on their lights daily. I was going 14 hrs on VHOs and 12 hrs on the older MH. Sounds like maybe that is too much. Any advice would be appreciated.

Dave

 

[Krish]

Welcome to RF Bryan as well as you Dave if I haven't welcomed you already On the bulbs, different bulbs need to be changed at different times. MH's are said to go 12 months before needing a change like Bryan suggested whereas T-5's need to be changed out sooner. To add to what was already mentioned, a bulb that has lost it's spectrum/ or is losing it's spectrum, can also promote algae to grow so that's another reason to stay on top of your bulb changes. As for a photo period, it all depends on what works for you. People usually run their lights from anywhere from 8 hours a day to 12, but totally up to you

 

[shallowreef]

Usually you can tell when your bulbs are getting old just by looking at your coral. If they are not opening up as much as usual then that could be a sign. Be sure to test your tank though to make sure everything is perfect just to be sure that its not something else.

 

[bobt2]

t-5s do not need to be changed sooner, the times are 14-18 months on the blues and 2 yrs on the 6500"s

 

[bryan1560]

I keep my actinic T-5 on for 9-10 hours and my MH only for around 6-8hrs. I was getting too much algea growing on my live rock and sand bed. The cutting back on the MH's helped out alot and my corals look spectacular. In the natural ocean the sun does not shine at it's brightest for 12-14 hours so why should you tank light be on that long. Shorten the time that the light are on and you sea life will be happier and you electricity bill will go down.

 

[DonW]

Bulb replacement intervals are different for every bulb and bulb type. Running any type of tube next to a open halide will shorten its life. If your vho's are just actinics they do much of nothing anyways so you can wait a little longer. Some halides are only good for 6months and other will go a full year. Like Shallowreef said alot depends on you corals. This also is the same for photo periods, depends on the bulb and light intensity. If you just follow suit with everyone else and dont make changes based on the reaction of your corals your going to have problems. One good example is the center bulb on my tank. If I dont change the bulb every 5 month the colony in the center will brown out, yet the other bulbs will go 9 months before anything starts browning. You just need to in tune to your tank.

Don

 

[bripen]

any truth to the rumor that double ended halides last longer--in general--than mogul based?

 

[jezzeaepi]

The problem with VHO's like you said Don is that they dont last long when combiend in a hood with MH's. The VHO's have a recomended operating temp in the high 70's where a MH runs so hot it can burn you, without any ill effect on the bulb. After as little as 3 months Im sure there is a noticeable drop in par, and possibly a shift in spectrum. If you want your flouro's to last longer try the t5HO. The benefit to using t5HO is that they have an recomended operating temp in high 90's. They should in theory retain their spectrum and PAR levels for a lot longer then the VHO's. Having some good air flow over your lights should help a lot too.

I am trying to settle the debate on when to change normally driven t5's once and for all. I talked to my roomate about it and he go me access to a spectrometer. Im going to take readings once a month for the next 9 months to see how fast the spectrum shifts. Cant wait for the results!

Peace

 

[bripen]

The problem with VHO's like you said Don is that they dont last long when combiend in a hood with MH's. The VHO's have a recomended operating temp in the high 70's where a MH runs so hot it can burn you, without any ill effect on the bulb. After as little as 3 months Im sure there is a noticeable drop in par, and possibly a shift in spectrum. If you want your flouro's to last longer try the t5HO. The benefit to using t5HO is that they have an recomended operating temp in high 90's. They should in theory retain their spectrum and PAR levels for a lot longer then the VHO's. Having some good air flow over your lights should help a lot too.

I am trying to settle the debate on when to change normally driven t5's once and for all. I talked to my roomate about it and he go me access to a spectrometer. Im going to take readings once a month for the next 9 months to see how fast the spectrum shifts. Cant wait for the results!

Peace

What about PC life with MH's?

 

[jezzeaepi]

Although I dont have data on hand about the recomended temp for PC's, I can tell you that my 192w pc fixture ran pretty hot for the last 7 months. Not only has the light visibly dropped off, but the spectrum has visbly changed. This is within only 7 months ona fixture NOT run with MH's. I can only imagine the PC's + MH will not last long.

Most people however only run t5/VHO/PC's with MH's to simulate dawn/dusk and to add some blue to 6.5k or 10k bulb. Most of your PAR is coming from the MH's, so the flouro's are really just a bonus imo if they add PAR. As long as they are still adding enough "blue" for you, then Id leave them.