How long do you run your MHs?

[Bbristow]

Curious how long most of you run your MHs. I have an aquapod 24gal and that is my only real source of light. The LEDs don't allow for much viewing. The light is a 75HQI. I have run it as much as 12hrs a day but am slowly cutting back due to some algea growth.

[zcatzmeow]

I run mine for about 8 hours. I also have the actinics running a longer cycle.

:)

[RayAllen]

I run my 250w MH at 6 hours but will increase it to 7 soon.

[CoryDude]

Pretty much the same: 8 hours for MH.

[ErikH]

12 hours for my mh and 9 for my T5s. I only have one 250 over my 75 and it's right in the middle, so in the early morning and late night it's the only light on, looks nice I think. :)

[SoLiD]

9 Hours a day. 4pm to 1am.... Hey, I'm a night owl. Besides, most of these fish came from the other side of the globe anyway. :bigsmile:

[glennr1978]

9 here as well. 1:30pm to 10:30pm. I too am a night owl, but I have to compromise with the wife and kid a little!!

[Kristy]

Big tank, MH for 6 hours (12-6pm) and T5s for 12 hours (8am-10pm)
Small tank, small viper MH 12 hours (10am to 10pm)

[apedroza]

8hrs for me!!! May increase it to 10 just because it's the only light I'm using at the moment!!

[dustint21]

For all of you that have them on for 8 hours or longer how long do the bulbs last? Do the double ended last longer than the mongul or vise versa?

[greenmako]

5 1/2 hours for Mh's
12 hrs for VHO's

[Bbristow]

Those running their MHs longer than 8hrs say 10 or 12. How long have you had your tank set up? And, Do you or have you had issues with algea growth?

[envy]

reef tank 8hrs MH
nano 10 hrs pc
fowlr 11 hrs florescent

[apedroza]

Not to high jack but what is teh distance from water to light on most of ya'lls tanks. Since I'm only running 1 light and want it to spread I currently have i about 5" above the water line. Is this too close??

[LoneStar]

Those running their MHs longer than 8hrs say 10 or 12. How long have you had your tank set up? And, Do you or have you had issues with algea growth?

Water chemistry would be more of an issue of algea growth than running lights for longer periods of time.

[JimD]

Not to high jack but what is teh distance from water to light on most of ya'lls tanks. Since I'm only running 1 light and want it to spread I currently have i about 5" above the water line. Is this too close??

That would really depend on the surface area of the tank and what you have in it.

[alton]

9 hours and I only have MH's. 2 1/2" above my glass tops with a fan to cool the glass tops. Install phosban or some other type of phosphate remover for algae control. Also SE last longer than DE but that also depends if you are using electronic ballast with Coral Vue Reef Flux lamps (18 months) or Giesmann DE lamps which also last a long time. Also just because your lights are only on six hours a day, does not mean your lamps will last twice as long as some one who runs there at 12 hours a day. Every time a lamp strikes it weakens the lamp life.

[ErikH]

SE lasts longer than DE?
It's a monday! :)

[ErikH]

Oh yeah, I don't have an algae problem, but as LS stated, the water quality is the key there.

[CoryDude]

9 Hours a day. 4pm to 1am.... Hey, I'm a night owl. Besides, most of these fish came from the other side of the globe anyway. :bigsmile:

Thought I was the only one w/lights on after midnight. When the tank was in our room, my wife always had fits w/it being on so late. I don't blame her, it is hard to sleep w/720watts of combined 03 and halide bulbs in the room

[alton]

I had DE lamps that went bad in 8 months. Switched to SE and have never looked back. My Boss has a Giesmann Fixure and lamps and they last over a year before Ken changes them out.

[ErikH]

Hmm, De bulbs are supposed to last 18 months, the same as T5s. I have bulbs that are over a year old @10+ hours per day. Everything else I have read has said that the lifetime of the DE bulbs is much longer than SE. If you are using 400w, that may be the case however as I know Bill had issues with the 400s.

[Bbristow]

Water chemistry would be more of an issue of algea growth than running lights for longer periods of time.

I have always thought this to be the case as well but I don't think this is always the only factor. I was speaking to a guy who has been doing this for years, doing talks around the US on the hobby ect. An expert. He realized that after the corals reach the peak photo exposure any time after that his MHs were feeding algae growth. He dialed the time back on his lights and his algae issues began to dissipate. I am starting to notice the same in my tank the algae growth has slowed and the coral continues to thrive. Maybe a coincidence. Wanted to see if anyone else had tried this. I have dealt with a small amount of hair algae and made all the other changes I can think of before this (change bulb, increase water flow, 20% monthly water changes, phosphate removers, ect.). The shorter photo period seems to be helping, at least in my case.

[Texreefer]

If you have determined the exact par needs of each coral and are measuring the par in your tank and have determined that you are reaching the saturation point this may be true.. but most of us cannot do this and most of us cannot provide enought light to reach the saturation point unless we have unnaturally long photo periods

[Bbristow]

Thanks for chiming in Texreefer. Your Perc-Osc clown is doing well by the way. Thanks again!

[Texreefer]

glad to hear