Overkill on lighting?

[M0oN]

I'm setting up an 8 foot by 2 foot by 20" tall tank, which is roughly 200 gallons...

I'm wondering if I'm going a bit overboard on lighting or not...

5 96 watt compact flourescents
3 55 watt compact flourescents

That totals roughly 3.2 watts per gallon, I'll be using pressurized co2 but I understand that the watt per gallon rule changes with tanks this large...

Am I going to be having algae problems up the wazoo?

[Debbie]

I don't think that is over kill. Like you said the watts per gallon rule changes with tanks that size. Another thing to take into consideration is the depth of the tank and you will need more watts per gallon for a tank that depth. The 2 watts per gallon works for tanks 18 inches deep.
I don't think you are going to have algae problems as long as you keep your nutrients in balance.

[Don_Lee]

Hate to say it, but I have a feeling you may have some algae/greenwater problems until you are able to get thing stabilized. I had a 180 gallon tank with 6 96 watt CF lights on it, and I finally had to buy a UV to clear up the greenwater. I think that CF lights are much brighter than regular flourescent lights.....

Don

[ChloroPhil]

MoON,

Are you using pre-assembled fixtures or retrofit kits? If I were to do a tank that large I'd just get four halide pendants and go with that. Over the long haul it'll be cheaper and easier. If you're into PC lights I'd go with 8 55w bulbs in whatever configuration you get them. Larger tanks can get by with a lower watt/gallon than smaller setups (starting at 90g and going down). Coverage is more important than amount and 2.0 wpg is fine over an eight foot tank. This is especially true if you're feeding rich foods.

Best,
Phil

[M0oN]

Phil,

What do you figure, 75 watt metal halide pendants?

The tank is going to have a canopy so I'll have to retrofit some double ended bulbs in it...but whatever, I work for a light company so they're cheap.

[ChloroPhil]

MOoN,

I'd go with 125 or 175 watt bulbs with one for every two feet of tank length.

There are a couple options. The first, and the one I've been considering most myself is to just take the flip top off the hood and use the part that sits on the tank as a sort of valence. You're going to want the bulbs between 8-12 inches from the water with some way of circulation...those things get HOT.

Aside from pendants, a lot of reef keepers are going to a mogul base arrangement with the lights in the hood. They're also using large computer cooling fans to keep air moving around in the hood and I hear it works out well. The only thing to worry about in a setup like this is your lights melting any unprotected equipment sitting above the tank like autofeeders and the like. If your hood is tall enough this could be the way to go. Don't worry about the watt/gallon rule with halides on a large tank. There's no correlation.

Best,
Phil

[vickie s]

Hey M0on,
My 125g has 4x96w aquarium Hobbiest Supply CF kits. This is a bit too much so I stagger when they come on and they are only all on at the same time for about 4 hours. This cuts the algea and I get good light coverage. I think the reflectors have alot to do with the brightness of the lights. I also added 2x13w red night lights that come on about a half hour before the lights go out at night. I have a 3inch fan that I got from Radio Shack to circulate air in the hood. It is on the timer with the second set of lights turn on. During the summer it makes a difference (we did not have air conditioning until last month). I put my ehiem feeder between the rows of lights on the center brace (acrylic tank) and do not have any problems with it. I did try the eheim liquidoser for ferts but the evaporation was terrible.
vickie

[Debbie]

Sorry I thought you had already bought the lighting. I had a similar set up on a 150 gallon that worked out well (minus one of the 55 watt compact fluroescents). I agree with Phil the metal hallides are the way to go since you have not bought the lighting yet.
I have 400 watt metal hallides on my reef tank and I have not had anything melt on me, the only problem is that the water still gets warm in the summer even though I have 2 large fans on either side of the hood. I think the pendants are a better idea...live and learn, I would use the pendants if I was to do it again.