MH and Center Brace

[netwurk]

I've recently ordered a 175W 10K AB MH setup and an Icecap Elec. Ballast. I've been reading about two things which I have some questions on.

My tank has the center brace and I've read this can cast a shadow or even worse melt the center brace. My question is if I already have two 65W PC, will this compensate for the shadow? I've seen most people with the shadow don't have flourescent supplements, but I may be wrong. I don't mind a slight shadow, but I don't want something extremely noticeable. Oh, my MH will rest about 5" from the waterline.

Also, I'm very concerned with the brace losing integrity due to heat. I really don't want to get overly complicated by building the acrylic brace. I don't think the MH is worth the integrity of the tank. Also, If I put a piece of acrylic between the MH and the brace will this reduce the amount of heat reaching the center brace? Will the MH melt the acrylic? I will be putting two RS fans on the canopy blowing in on the MH.

Thanks!:p

[MAS]

If you have an AGA, it will take quite a few years with proper care before I would worry about its integrity. I used to own an AGA65g. I ran 2 mh's over the tank so as to get rid of the potential shadow. If your running one directly over it, looking straight on it will still be noticeable, even with PC's. If your running 2 mh's dont even worry about it.

cheers
MAS

[netwurk]

Thanks for the response MAS. I find it amazing that I'm confronted with the problem of the shadow. I feel like selling the MH and I haven't even received it yet. I really can't afford two at this time. I've heard some people bending a spyder type reflector to reduce the shadow. Maybe I might just try it, but I'm not sure how effective it will be.

Also, does the 175MH create a lot less heat than a 250 or 400? If it does generate a lot less heat then I'm sure the center brace will not degrade much due to the heat.

[MrClean]

Melting the center brace is a valid concern. I melted one on a Perfecto years back with a 250w halide 4" above it. I had a fan in the canopy, but not blowing directly over the brace.

The front of the tank bowed considerably before I lowered the water level. I feared an explosive failure. I ended up putting a stainless steel frame around the top.

I guess the moral is if you put a halide over the brace, bad things could happen.

[netwurk]

OK, I think I'm convinced that I should not attempt to install this MH. I think there's too many negative variables involved and I'm not pushing it up to two MH's.

[MalHavoc]

Why not mount the light higher up? That'll relieve some of the heat issue as well as make the shadows less noticeable since the fixture is further away.

Some people also put a strip of duct tape along the top of the brace to keep the light from directly shining on it. Lots of UV light can break plastic down.

[netwurk]

I really can't mount it any higher up because my canopy won't allow it, and I don't want to drill through it. The strip of duct tape is a good idea. :)

[areefer]

How about getting a strip of glass and silicone it on as a brace.

[netwurk]

I wouldn't mind siliconing a piece of glass to the frame, but the way I see it the center brace it has now should be stronger because it's a one-piece unit with the rest of the surrounding moulding. This leaves all of the other panes in perfect proportion to withstand the pressure.

I hope I'm wrong with that though.

If I would put the glass as a replacement is there any better way of attaching it to the main glass panes or moulding than silicone? I don't think this is strong enough.

Please let me know if anyone has any ideas.

[MAS]

A single 175 mh bulb over a 36"x18" tank is going to be fine, doubt heat issues will arise, depends where you live too of course.

I used to run dual 400's over a tank the size your talking about. WIth a pair of fans temp was always fine(but I had a room AC too at that time). Personally I think you should keep the 175, run it in the center, then when funds are available add a 2nd one. MH's are the way to go. Please dont get buyer's remorse from my comments. Its a great setup, and there are lots of great bulbs available in the 175 watt setup. Feel confident on your purchase. If you dont want it, you can alwyas give it to me! :D I always can find use for another light. I already have 3600 watts worth of lighting on my tanks, so whats another 175 watts?! :lol:

[netwurk]

MAS, was that 3600 or 360????

If it's 3600W then I would really like to know how you sleep at night?

I have major buyers remorse....I can't believe the situation has gotten so overly complicated.

Thanks for the reassurance....Eventhough I've already called all my friends to see if they'll do a swap or buy them off me, etc.....but they all have center braces....

I guess the moral of this story is you should always buy MH's in pairs! :)

[netwurk]

I was wondering if anyone has built the brace that's in the attached picture? If so, then what are your feelings with the results? Was it stronger? Any problems?

I think this is pretty easy to build. I'll get a 1/2" piece of acrylic maybe 4" wide the exact measurement of the interior length from front glass pane to rear glass pane. Then get silicone and attach it to both the front and rear glass to secure the acrylic brace. I'll follow that up by making three holes on each side of the existing brace. I'll attach the acrylic to the existing center brace via the 6 holes with some nylon screws. Finally, I'll Dremel the existing brace off on the interior side of the nylon screws to give me a clear center piece.

Do you think this will be stronger than the existing brace??
Does anyone think this is a bad idea???

If you recommend it then what are your recommendations for the silicone I should use? I would like to use the silicon they use to build tanks with.

Sorry for all the questions, but I want to do this right, ONCE! :)

Thanks Everyone!!!!

BTW, I think I've fired up a storm on this forum. I've noticed three other posts after mine concerning the center brace and MH combo.

[MAS]

Hey bro, yeah its 3600 watts. No joke there at all. I have ALOT of light fixtures for grow out tanks and live rock. My love for this hobby is turning into a business for me basically! :lol: I dont kid around when I state I have alot of hands on experience with literally every imaginable light fixture or protein skimmer,pump etc on the market. I have been swapping through thousands of dollars worth of equipment over the last 3-4 years to get an honest feel for quality products on the market. I try my best to give a neutral opinion on a product. Whether I use em/recommend em or not. Seriously though. I think that 175 will be sweet over the tank. Its a small wattage mh bulb so adding another in the future will be far from overpowering. I think you should at the very least try it out over your tank. If there is a noticeable shadow in the center which doesnt appeal to you then maybe down the road you can think about adding another fixture. This is will give you alot of fun options too. Including seperate control for each light fixture which will allow you to do a cool sunrise/sunset effect with timers or a contrller. Allow you to also vary the intensity of the light too which I feel is important to corals. Its not always noontime in the pacific you know!

:lol:

Like I said, be confident with your purchase, experiment with it, this is the best way to gain knowledge for individuals. As great as online info boards like this are, nothing, and I mean absolutely nothing compares to hands on experience! This is probably the best advise I can ever give. Take advantage of the new equipment and have fun experimenting, not just with looks, but coral growth and coloration, fish behavior/habits, effects of the fauna etc. The books and us give you a good place from where to begin your search and experimentation, but implementing it yourself is the best thing of all!

cheers
MAS :D

[gbtower]

Why not just mount the light slightly off center? Ever heard of the rule of thirds? You could make it look pretty interesting. Just a thought.

Gerald

[netwurk]

I haven't tried it, but some people said it doesn't look to good. Who knows, I'm planning to try every which way!:eek1:

[reef92109]

I'm currently trying to use a folded piece on tin foil sitting on top of the brace to minimize the heat. So far so good.