Lighting Period Question

luisprado

New member
I have 144w PC lights right now and I run them 10 hrs a day. I will be switching over to a 70w MH in the next couple of days or so.

How much time will I need to have the lights on in my tank with the 70w MH?

Thanks.
 
Is it a used or a new MH? Be careful of shocking the tank with the change in lighting, imho. Especially if it is a new unit and new bulbs. PCs get your tank used to a much lower spectrum, and MH's can freak the corals out a bit because the zooxanthellae aren't used to it. Sort of like getting a sunburn the first time you tan for the summer- not enough tan to protect you from higher levels of light.

Get them used to it gradually by judicious use of shading, shortened photoperiod, etc.

Hope this helped and Grats! on the MH upgrade!
Laurie
 
well, you will want to acclimate the tank to the new light by either slowly lowering the MH to the tank (over a few days)or by using a reduced photoperiod, and increasing the time (over a few days) eventually you can run it the same 10hrs p/day.
Personnally i run my MB7 w/ a 70W MH for about 8 hours. I dont need the extra heat.

I think the 70W may not be enough for your 24G. you may want to suppliment it with some of your PCs. JMO...
 
The spectrum is different true and it could shock them yes... but probably will be more of a shock getting almost half the light as they used to... 70W is not enough for most stuff IMO that is right under 3W per gallon...
 
I heard watts per gallon is not an accurate measure. Especially when comparing PC to MH. So a 7Ow MH in a 24g nanocube is not enough?

Does anyone else have any opinions or advice?
 
WPG is not accurate in SW. But, 70W is a lot less than they were used to. I would look for at least a 150 DE or even a 175/250.
 
agreed with the wattage problem. Watts/gallon isn't accurate anymore but can still be used to represent lighting. IMO, the only difference between MH and flourescents is the focus of the light. Not necessarily the color spectrum or intesity. MHs look brighter because the light comes from a smaller starting point; whereas, Flourescents are longer bulbs and are more like flood lights then spot lights. If you have a deep tank you will need MH. But if the tank is long then Flourescents with do just fine. 70 watts is not enough compared to the 144. If you want to up the lighting. Use the 70mh with the 144. Run them both.
 
Wow, that is an excellent reply jessiesgrrl & MinibowMatt. That's what I call hitting the nail on the head. Cud-do's bigtime.

I would only add that you should make your acclimation period at least 4 weeks, slow and gradual as mentioned above. Your major concern would be prolonged retraction, potential bleaching and and yes, even mortality in some cases.

I would heed Jessie and Mini's advice 100%.

Mucho
 
Hey Mucho, I have a question for you- I have often wondered in situations like this if changing out varying densities of a material in between the new light and the glass would help block enough of the new light to acclimate the tank without having to move established corals, etc to areas of shade during acclimation to the new light?

For example textured or tinted glass, plexiglass, clear glass, and then nothing?

:D
Laurie
 
By all means, you can use bridle vail, coarse fish netting, I used window screening. As I recalled, about 6 or 7 layers, can't remember. I played it very safe as many of these materials are combustible. I placed my old glass tops back on my tank, then the many layers of whatever material you choose to use, followed by another layer or glass to prevent the material from possibly igniting from the heat of your MH lighting. I used Starphire glass to insure that I wasn't filtering too much light. It waorked like a charm for me.

Mucho
 
Huh... pretty ingenious way to go about it you have there. Being lazy myself, I was trying to think of different thicknesses of glass or actual transparent materials that you could just switch out one at a time, or take one off at a time from a stack...

I even thought about that colored saran wrap they sell. Wrapped around glass, it guaranteed reflection of that color at least back up from the glass. If you put a few colors on and then took them off one at a time..? Also, the wrinkling and unevenness (Is that even a word??) would help refract the light. but, it may melt...


Maybe if you stapled the nettign to frames, and then stacked the slender framing and took it off one at a time??

:D
Laurie
 
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