MH Pendant Mounting Height

[jonboyb]

Developing the mounting system for my 400 w Lumenmax Elite pendant and trying to get a feel for height off the water. It's on a 30"x30" cube and my system will have minor adjustability (maybe 4" +/-) but I need to be close to start with if possible. What height are you guys using. 24" depth to the sandbed. I was thinking of mounting it at 8" above the water which would give me a possible range of 6-10" available.

 

[porpoiseaquatics]

I have the bottom of my fixture at about 10" from the water surface. That puts my bulb at about 15" from the surface. My pendant is a DIY setup so I put my bulb parallel to the water surface instead of perpendicular. I thought that would actually give me more coverage.

 

[snowmansnow]

I use to run a 400w pendant over a 24" cube. I did not run a chiller, only a fan on the back of the tank. I actually had to crank that thing up to about a foot and a half in order to keep my temp anywhere under 82. 8" IMO will be too close for that pendant.

Just my opinion.

B

 

[porpoiseaquatics]

I didn't even to think to mention about temps in my response. Snowman is absolutely correct. In my 29 biocube with a 175...I had to put a 4" fan on the back to keep it down. On my 92 reef...the 400 where I have it now keeps a constant 79 degrees on the tank without adding any fans. I run a heater at night just to keep the temp even.

 

[snowmansnow]

ya .. i think if you drop that 400w down to 8" without a substantial cooling system you'll be boiling pretty quick.

b

 

[jonboyb]

Cooling isn't an issue, just looking for optimum coverage and par.

 

[snowmansnow]

I would consult the manf of the reflector then.

b

 

[darren24]

10-11 inches.

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[jonboyb]

Dang......seeing the amount of reflection you have makes me reconsider my full canopy:sad: The tank sits next to the couch in my mancave. That reflection will interfere with my TV viewing

You did help me make up my mind to paint the back though

 

[darren24]

It depends. I have the large Lumenbrites and they are LARGE. If you have a smaller unit it may not be as bad. This is in my "Man Office" and it does not bother me when on the computer etc.

 

[snowmansnow]

I've done open top 3 sided canopies for tanks before that just slide on the front and are open on the top and back..

it would keep the light in the tank and out of the room.. and they are wicked easy to make.

b

 

[jonboyb]

Darren24;398484 wrote: It depends. I have the large Lumenbrites and they are LARGE. If you have a smaller unit it may not be as bad. This is in my "Man Office" and it does not bother me when on the computer etc.

The Lumenmax Elite is only 15" square and 6" tall but tested as good as the much larger reflectors (just pricey). The small size made the extra $$$ worth it on my application.

 

[darren24]

Yea these are 22in across I believe... You should be ok on the reflection / spill over issue.