Tank Cross braces casting a shadow on my reef!

[themaddhatter]

I just recently installed 2 250W DE Metal Halide pendants on my 125 Gallon (6') tank. the tank is by all glass, and has two plastic cross braces across the top (1/3 & 2/3). I spaced my lights out the same way and as was bound to happen, ended up w/ my lights directly above the braces, which cast a very prominent shadow (clearly visible in photograhs too) right below each brace.

My question is, would moving each pendant a couple of inches to the outside alleviate this? I know ideally I should have 3 pendants for 6', but I find it bright enough already and don't really want to add another if I can help in.

If I do move them a couple inches each to the outside, and get the brace out of the "center" of the light bulbs, I'm hoping the shadows will disappear.. I just hope it doesn't kill the in tensity at the middle of the tank, where I want most of my corals to go.

any suggestions?!!

[bogg]

Your answer is here http://www.reefcentral.com/forums/fo...s=&forumid=399
http://www.eloseurope.com/index.php?...mid=76&lang=en

[DarG]

You have two options. Remove the braces and replace with clear acrylic. Do a search here (if you can) there are fairly "safe" ways to do this and definitely unsafe ways to do this ... no, make that stupid ways to try and do it but lose the tank in the process.

Option two is to move the reflectors/pendants and add one.
This is the safest option and it would get you that 3rd pendant which you really would be better off having on your 6 foot tank.
Well actually, the larger reflectors will cover 3 feet, or close anyway. From what I've read anyway. But 3 is probably the "right" way to go or atleast the best way to go in your situation.

My 90 has a single center brace. 2 Lumenmax 3 DE reflectors and no center brace shadow ... I mention that just in case you were wondering if moving them and centering then between braces would definitely fix the shadow.

[themaddhatter]

Hi Bogg.... no idea what those links are supposed to tell me....

Hi DarG,

I'm definitely not about to mess w/ the braces.. My last tank flooded the basement, so I'm paranoid. I measured from each pendant to the end of the tank and also between the pendants. The way I have it now, I end up w/ 18.5" from the end of the pendants to each respective tank end. Between the two pendants is only 14". I was thinking to try moving the lights 2 inches over so its around 16" between the two pendants and also to each ned. This would (hopefully) still get me enough light in the middle, and also get the center of my bulb out of the way of the braces. Additional bonus I just got was complete polished stainless steel wrap for the inside of my canopy, which I'm hoping will help redistribute some light. '

I don't know if this will eliminate the problem or not. I'm hoping it does, but if not, I guess I'll have to eventually get another light.

[DarG]

The problem is that even though you get the bulb center off from center of the brace, the reflected light will still catch the brace and cause the shadow. But I'm not sure I understand your set-up. Is it one of the fixtures where the entire inside is a reflector for the halides or do you have an actual pendant or seperate reflector for each halide? Seperate pendants can easily be positioned, centered between braces so the brace doesnt cast a shadow. But Im not sure if you would totally be able to eliminate a shadow if using a fixture where the reflector is the entire inner surface (like some of the Hamilton combo fixtures). I havent used one of those with halides so I dont know for sure. I'm sure that even with that type, having the bulbs centered between braces instead of over them would certainly help because direct light wont hit the brace as much, but not sure if it would totally eliminate it.