MH Questions
Printed From: Utah Reefs
Category: Specialized Discussion
Forum Name: Equipment
Forum Description: This is the place to ask question about reef equipment.
URL: http://www.utahreefs.com/forum/forum_posts.asp?TID=43058
Printed Date: June 19 2026 at 5:24pm
Software Version: Web Wiz Forums 12.03 - http://www.webwizforums.com
Topic: MH Questions
Posted By: SGH360
Subject: MH Questions
Date Posted: August 27 2010 at 2:42am
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Hello i just got a few question about MH
Is 2 400MH for a 90G be too much? will it fry corals?
Using those lights do they need a fan? or will they be ok without one?
How can you tell when they are up to their cycle of life?
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Replies:
Posted By: Jeffs_little_ocean
Date Posted: August 27 2010 at 7:54am
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IMO 800 watts over a 90 gallon would be too much and I would think most corals would hate it, although certain SPS would be fine. Mogul based MH do generate alot of heat, just watch your water temp and see what it does. If it does get too high, a fan blowing across the surface should help. And the general rule is replace MH bulbs anually. ------------- Life is good....right? |
Posted By: Mark Peterson
Date Posted: August 27 2010 at 9:27am
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I agree. But it depends on what other light is also used. For years I had a 75 gal with 2x175MH and 4 VHO, but it was in the window getting sunlight all morning so the MH didn't go on until noon. All MH are hot. Unless you keep the room at 65 you will probably need a fan to blow across the water while the lights are on. ------------- Reefkeeping Tips, & quick, easy setup tricks: www.utahreefs.com/forum/forum_posts.asp?TID=9244 Pay it forward - become a paid WMAS member 
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Posted By: sterling18
Date Posted: August 27 2010 at 11:26am
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Depends on what Kelvin rating on the bulb you want to use.
For example a 6.5K or 10K bulb, over your tank which should be approx 26 inches tall, most of your stuff will be on the bottom or might get bleached.
But if you went with a 20K bulb over your tank, with softies and LPS on the middle to bottom and sps near the top, you should be ok.
You get higher par ratings with 6.5K and 10K bulbs than a 20K bulb since they simulate different lighting in different depths in the ocean.
It is a lot of light and you might have heat issues, but if your sump was a 120 gallons in another room, you might be able to get away with it.
Just my opinion. |
Posted By: SGH360
Date Posted: August 27 2010 at 11:33am
| thx guys i had a feeling these were to strong. i'll start searching for T5 shoot if only i knew what to look for |
Posted By: SGH360
Date Posted: September 06 2010 at 10:48pm
| what are good options 2x250W or 2x150W? i dont see alot of options of bulb of 175W its going to be for a 75G its 20IN deep |
Posted By: Luckedout
Date Posted: September 06 2010 at 10:50pm
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You would be fine with either 150w or 250w over a 75g.
------------- -Ben 90g Mixed reef www.body-balancechiropractic.com |
Posted By: SGH360
Date Posted: September 07 2010 at 1:11am
| will 2x150 support sps? |
Posted By: DLindquist
Date Posted: September 10 2010 at 8:05am
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I have 2 x 14K 175W MH's and 2 Super Actinic 110 VHO's over my 90 gallon and have been able to grow just about anything. Some of my SPS are even middle to lower in the tank. I run a fan on top to cool out the canopy. ------------- A government strong enough to give you everything you want, is powerful enough to take everything you have. |