ATI Powermodule for ca.200L (56US gal) tank??

I am currently running 4x24W T5s DIY fixtures and a load of LEDs over my 200L DT. I really like the ATI powermodules and I'm considering an upgrade although I'm not sure if I should go for the 6x24W model or the 8x39W model. The area at the top of my tank is 910mm x 440mm (L x W). The 6x24Watt model is 585mm x 345mm (L x W) to me this seems a bit too short.
The 8x39Watt model is almost the same dimensions as the area at the top of the tank; 880mm x 445mm (L x W)
The 39Watt model means a 2.5mm overhang on the back and front.
I prefer the 8 tubes to 6 and the 24W model just seems a bit small considering I want to start keeping SPS and was hoping to redo my aquascape so that I can have 2 outcrops with corals in the middle and sides of my tank.

What would be best, to completely cover the top of my tank with T5s using the 39 watt or go for the 24 watt and not have as good coverage on the sides but would possibly be more compact and easier to mount?
Any input greatly appreciated.

 

I personally don't see any advantage to having a lighting fixture overhanging the top of one's tank. In my mind, it would be an eyesore.

For the extra wattage it would afford, IMO it doesn't make sense to light ANY area outside your tank for any reason.

Just my opinion. If you're really looking for wattage, have you considered halides? Not that there's anything wrong with T5's, so long as the height of the tank permits.

 

I just prefer T5s for the different colour spectrums, plus the energy savings of T5s over MHs. My tank is 22" deep (19" deep to the top of the substrate).

 

Do you think 2.5mm overhang on the front and back would cause it to be that much of an eyesore?

 

I don't think it would look bad considering it's a powermodule,also the outer 2 bulbs can be turned off if too much light is escaping although that wouldn't be ideal obviously.

 

I haven't done my metric conversions in a while so I might be rusty.. I think if I am right that your tank in inches would be 35ishx17ish?... If thats the case 6 lamps would be more than fine. In my eyes you will be wasting light and energy witht the 8 lamps lighting the panes of glass and an area that you will most likely not be putting any corals... If you want to go big or go home do the 8 lamp but if it was my tank at home I would stay with the 6'er....

Good luck with a great unit!

 

I'm going to go for the 6'er, thank you for your replies.

 

Depending on your type of tank, 100% SPS, Mixed reef, LPS dominating, I would suggest getting a 6 lamp instead of having the light overhang. What alot of people don't realize is that the powermodule isn't like most other T5 fixtures. It gives off so much more PAR because of the reflectors/active cooling. The highest PAR measured in my tank was over 520, the lowest in the sandbed was over 320. What I can tell you from IME, is that a ATI Powermodule is one beast of a light.

I used to have a 36"x24"x16" acrylic tank with a 6x39W Powermodule. That tank was 90% SPS, and it thrived. I thought I would try a bigger light, and really cook my corals, so last Christmas, my wife got me a 10x39W. Basically the size of the light covered the whole top of the tank. I had to have my light 12"+ above the waterline to keep my corals from bleaching out. All LPS had to be placed under overhangs to maintain color.

I decided I needed to build a tank for this light, and went with a 40"x28"x22" custom tank. The light looks great over the tank, but even thought there is a 2" gap between side panels and 4" gap between the front and back panels, I still need to have my LPS, mainly chalices under ledges. Many Acros need to be placed on the sandbed or with shadowing to maintain their desired colors. I have to keep a ORA Red Planet under an ledge to get it near its desired color.

So if you are going to have a mainly SPS tank get the 6x39W, but if you want a mixed reef, then you may want to consider the 6x24W.

 

Wow thank you for sharing your experience with the powermodule, this really helps. I will be wanting to keep SPS I have a second tank with less lighting to add my softies to and LPS.