[Bamaguy]

I just set a new tank. Down the road (a year or so) I want to convert from FOWLR to reef when I can swing about 50lbs of live rock and a new lighting system. I've heard the rule of thumb for polyps and mushrooms is about 3 watts per gallon and wanted to check and see if that is standard?
I've seen 6X54 watt T5 fixtures that would fit that bill for my 90 gallon. Would that work?

[NATIVEVAMAN]

If you have individual reflectors on that fixture you can probably sps.

[pogodzib]

The WPG rule is a very basic rule that for the most part shouldn't even be used because every tank has a different shape and different types of lighting penetrate the water better than others. This is a very good post that I feel is much more accurate.

Originally Posted by Mcintosh
I think the best way to go about the lighting issue is to break it up a bit.
High light - light loving animals throughout the tank, from the top of the tank to the bottom, clams on the bottom of the tank.
Medium light - Light loving animals at the top of the tank, lower light required species at the bottom.
Low light - Really, a softy tank. Maybe a few montis or LPS up top, and very low light animals at the bottom of the tank.

High light--
18 inch deep tank or less 150 HQI/175 MH plus supplemental lights per 2 square feet.
24 inch deep tank or less 250 W MH plus supp. lights per 2 square feet.
more than 24 inches 400W or greater per 2 square feet.

If using T-5's, as many T-5's lights as will fit across the tank (Probably need 8 T-5's spanning the full tank)

Medium Light --
18 - VHO/PC @ minimum of 6W per gallon or 70w MH/poor PAR 150/175, no supp.
24 - 150/175W MH or approx. 4 T-5's spanning the tank
>24 - 250W MH or approx 6 T-5's spanning tank

Low light --
18 - normal output Fluorescents over tank (ie 4 40W fluo. over 55 gallon tank)
24 - VHO/PC's no more than 3 or 4 watts per gallon (4 65W PC's over 90 gallon tank)
>24 - same as 24 inch tank above.

HTH. And feel free to flame me on any of the above statements. I know that there are exceptions, and I am more than happy to hear about them.

[Bamaguy]

I found that post this morning. Someone should sticky that. It's very helpful. Thanks!

[pogodzib]

Your right. That thread is very useful and would probably benefit many people and help them realize that there is a better way to determine lighting needs besides the WPG rule. I sticky'd the thread and will maybe move it into the "Equipment" forum area once the current discussions are completed.

[jimw369]

Originally Posted by pogodzib

The WPG rule is a very basic rule that for the most part shouldn't even be used because every tank has a different shape and different types of lighting penetrate the water better than others. This is a very good post that I feel is much more accurate.

I have a 90 gal tank 24 tall with a 8 lamp tek light over it. I am currently running only 4 lamps. I have found thru testing the par in my tank that once you reach a certain point the tank is saturated with light and adding more lamps does not raise par anymore (very little) unless you put in more lamps with lower kelvin. Moral of the story: Once you reach a certain point more lamps does not mean more light.

I am being told that 1 T5 bulb 4" off the water in a quality 9 bend reflector covers 6" of clear water to a depth of
20" effeciently and adding more bulbs covering the same area is only wasting energy. Based on what I see in my tank this is true.

[Bamaguy]

Originally Posted by jimw369

I have a 90 gal tank 24 tall with a 8 lamp tek light over it. I am currently running only 4 lamps. I have found thru testing the par in my tank that once you reach a certain point the tank is saturated with light and adding more lamps does not raise par anymore (very little) unless you put in more lamps with lower kelvin. Moral of the story: Once you reach a certain point more lamps does not mean more light.

I am being told that 1 T5 bulb 4" off the water in a quality 9 bend reflector covers 6" of clear water to a depth of
20" effeciently and adding more bulbs covering the same area is only wasting energy. Based on what I see in my tank this is true.

So basically we have the same tank in lighting terms. Could you give me some idea of the 4 bulbs you are using including wattage, kevin, refelctors, brand etc. I would think that your setup would work for most 90 gallons with 24" depth then? In the long run, I could go with a 4 bulb T5 setup as opposed to a 6 or an 8 as long as the reflectors and bulbs reached their maximum potential? Is this correct?