Building light hood?

[JerryI]

I'm a newbie to reef tanks, switching from a fish w/LR to a reef environment in my 55 Gal plexiglass tank. I know I wilhave to give up a beautiful Picasso Trigger I've had for 4 years but the challenge of building a reef is one I'm looking forward to.

I have the filtration set up and am working on the lighting, looking currently at MH and a flourescent combo. I plan on building the hood and have some questions aboutthe dimensions and construction. One is the height needed for the MH to prevent melting the plexiglass top. Other suggestions are encouraged as I'm sure there are things I haven't thought about that I should be considering.

Looking forward to participation in this forum

Thanks

jerry

[Minnreefer]

Welcome to The Reef Tank
I have read a few things about putting MH over an acrilic tank. One have as much air as possible at least 8" between the MH and the tank top. I have also heard of building another layer on top of your present top about an inch off with air in between to absorb most of the heat and uv light.
I would plan on getting an icecap 660 for VHO to add to the MH. the icecap is very versital and you will probably use it on any future tanks.
Welcome again
Jonathan

[dgosho]

What kind of wood are you going to use?

Have you ever built anything out of wood before?

One thing that I would recomend is going as metal-less on the hood as possible. The only hardware on my hood are the hindges and the hindge screws.

The main tips in building a hood that I could give you are to make sure that you plan your doors on it carefully. When I designed mine, i knew that I wanted to get into the tank w/o removing the hood so I built it with a completely open front with a door that is the entire size of the front that lifts upward so it isn't in the way when I am messing around in there. The door hindges are sturdy ones that lock open so the door won't fall back down.

The other thing was that I wanted easy access to changing my lights so I made it so that the top of the hood lifts up and back.

I also used as much solid wood as I could afford and coated it heavily with a water-proof finish.

If you have never done any wood-working before it might be a good idea to pick up a small book on cabinet making basics.

Have fun!

[FishDaddy]

Hi Jerry,

Good to have you with us!
Switching the 55 to a reef could give you an excuse to buy the Picasso a 6' FO Tank!!!!
Heat is an issue with MH lights.. many place their lights 8-12" off the water. Some have them lower but in either case, fans and vent spaces will help keep temps down.
Dbmet just finished this great looking hood for his 75. The front hinges up for reaching into the tank as well as the top for access to the lights, as David also suggested:
http://www.thereeftank.com/cgi-bin/u...c&f=1&t=004382
Jon has good points about protecting the top surfaces, especially the center cross brace, from excess heat.
Two 250 watt or 400 watt MH lights would be great on this tank, enabling you to be able to keep most any coral or clams. 175's don't have the selection of bulb spectrums that 250/400 have.

One other thought: while you already have the 55, a 75 makes a much better reef tank! I have 55 and sure wish I had that extra front to back depth for lighting options and more space underneath for a sump. The extra 6" makes a big difference in aquascaping and the fish bioload you can keep. One of these days I'll move mine into a 75.
Again, welcome!
Dick

[ 08-21-2001: Message edited by: FishDaddy ]

[JerryI]

Thanks for all the great feedback. A 75 g tank would be nice but the 55 is a step up from the original 29 that I had till it sprang a leak. That jump was great for my 3 fishes and the live rock I have in it.

For now the wet-dry filter, protein skimmer, pumps and everything just fit under the cabinet base, though it is tight in there and I don't look forward to having to do any heavy maintenance down there.

As to the top, I have a pretty decent woodshop in my basement, shopsmith, standalone table saw, planer, jointer, etc and I have done enough sawdust making that I should be able to put this together.

I was planning on using marine grade plywood and then finishing with several coats of black paint or laminate to match the glossy black base cabinet.

Cooling fans in the ends are also part of the plan. Doing some more reading this afternoon I am now a bit concerned over the ballast for the MH lamps. I understand they can really get hot. I know the little one for the single flourescent on my tank now gets too hot to touch and with a couple of MH and possible another tube - I wonder if it would be better to keep them external to the hood.

I also plan to have the front hinged to provide access, either brass of stainless hinges and screws.

One other question. Which is preferable -covering the tank with plexiglass, or glass or leaving it open to the lights? Besides keeping the inhabitants in the tank and reducing evaporation and splashes I read today that it is important to cover the tank to reduce UV radiation.

Thanks again for all the suggestions. I've got everything to learn about this new adventure I'm on and can use all the help I can get.

Jerry

[Hermit]

Welcome Jerry,

I just finished a hood for my 55. A couple of things I learned.
1) Notch out for the hinges on the front door. The light coming through the gap is enough to drive a person crazier.

2) Use hinges with removable pins. This way you can lift off the entire door.

Just my 0.02.
Kris

[Rick O]

Hi Jerry,

Welcome to TRT.

I would definately remote mount the ballasts. Besides being hot they are quite heavy. I would not use any covering over the water. You are going to need a lot of evaporation for cooling unless you get a chiller. I assume you're planning to use two MH.? I have a four foot tank with two MH. I have two Icecap fans, one is blowing in and the other out. I'm able to keep my tank temp at 82 or below in the middle of the day.

HTH,
Rick

[JerryI]

Thanks Rick, one more piece of the puzzle.

BTW, what is the distance from the MH tubes t the top of the tank in your setup? Also, is your hood enclosed on all four sides? I was thinking about leaving the back open - but then I saw some photos of a top under various stages of construction and operation and it looks like there is a lot of light leakage and an open back might not be a good idea.

Jerry

[Rick O]

The bulbs are approximately seven inches above the water. My hood comes down in the front and back to about three inches above the water but there is a lot of light reflection in the room. I've had to drape a towel over the front of the hood until I can get around to installing another piece of wood to correct this.

Rick