MH Lights ?

[marinemarty]

How far should MH lights sit above the tank? I am looking at either a pair of 250 watt bulbs or 3 175 watt bulbs for a 125 AGA.
Thank You
Martin

 

[marinemarty]

Then how is one suppose to have lights in the new Modern series
canopy which only has a clearance of 41/2 inches? Thank You
Martin

 

[wagirl81]

unless you modify the canopy to sit higher, then you realy cant.
I would also go with 3 175's or even 3 250's on your tank........I have a 72g and have 2 250's and I have to Hang them from the celing. hth
~Randy~

 

[richard rendos]

He said Modern Series...that is a series of canopies from All-Glass I believe and they are low profile. They can be modified to sit higher.

 

[smalltimer]

Or, check out the PFO HQI pendent, it can be cut into a hood, the ballast is remote and the 250 watt has the photosyntis, spelling??, rating of a 400 watt, they are a litte pricey but worth it. I have a 250, 4" above the water to the protective glass, and the bulb is about 2" above that. Only down side, you see the 4x10 black hood coming out of the top of the canopy, up side, I run cooler with 250 watt mh, and 2 40 watt actinic, than I did with 2 55 watt days, and 2 40 watt actinic.....believe it or not, the pendent is vented on the top so all of the heat goes up and all the light goes down, and as far as the rating of the bulb, check out this link, it's VERY detailed, but look at the rating of the HQI compared to the Coralife bulbs and others....The 400 watt corallife has the same ppfd rating as the 250 watt HQI that comes in the PFO fixture...
http://www.animalnetwork.com/fish2/a.../2/default.asp
The PPFD RATING is the rating is the important rating for photosysnthsis