Can 2 400W radiums cover a 6' tank?

[Captain Clam]

Please chime in here Perry. I know the general rule for a 250W MH is that it covers a 2'x2' square. Can a 400W radium cover more? I'm wondering if I can hang 2 400W bulbs over my 135. The tank dimensions are 72"x18"x24". The tank has a pretty beefy centerbrace so I'm not sure how much good a light in the center would be anyway. I am looking at the deal from Ocean Encounters that has the sunlight supply reef optics reflector and the sunlight supply dual ballast. I assume this is an appropriate ballast for these bulbs. If the two 400's can't cover the whole tank themselves, I could put a 150W HQI over the center so it didn't heat up the brace too much, and use a couple of 24" actnic VHO's in the center to help match the color of the 150 to the 400's. Thanks for ideas or input.

[tendar]

250w or a 400w it doesnt matter they cover the area just one is more intense. 2'x2' is thier main coverage but it is possible to hang only 2 bulbs over a 6' areajust put the more light loving corals under the bulbs and the lower light corals on the sides. I would hand some VHO to help fill in the space over all and you wont be able to tell the difference.

[Captain Clam]

Thanks tendar. That's kind of what I'm thinking. I'll spread the 400's evenly and add some actnic white VHO's in the middle. That should save a bundle up front. Thanks for the input.

[naser]

i tried that on my 120... huge darkspot in the middle... im now running three 250's//

[Captain Clam]

naser - what are the dimensions on your tank and does it have a center brace? Part of my concern is that the center brace is pretty wide on my tank so I'm not sure how much useable light will be transmitted through it anyway. If I use 3 pendants there pretty much has to be one light right over that brace.

[chewie]

Captain Clam,

Is your tank a tru-vue? I think we have the same tank. Currently I'm running 2 400w radiums and I like it, but I still want more light. With good reflectors, 2 400's cover the 6' tank OK but I'm gonna add 2 more 250's to the sides and the 400's to the middle(not over the brace).

My original plan was just like yours even with the VHO's in the middle. I ditched the VHO's because they didn't make too much of a difference to the brightness of the center of the tank.

I'll see if I can get a pic for you but my bulbs are mounted parallel to the front of the tank with PFO reflectors(parallel). I wish I would have went with the parabolic reflector but for now I'm happy.

Good luck

Jon

[PerryinCA]

Sorry for the late reply.

It depends on the needs of the tank, and aquascaping, the coral....

If you are looking for high lighting across a tank that size, two 400w systems will not do it.

400w may be able to cover more space (with the use of a larger reflector), but the reason the 400w radium is used is because of the large reduction in output seen when one uses a higher k lamps, thus negating the increase in wattage.

I think that with these lamps, you are best to stick with the old 2 x 2.


-Perry