MH... 175 or 250 for a 75 gallon tank?

[sharky71]

I'm ready to take the MH plunge. I've been running 200W of Power Compact on my tank for the past 6 months and I'm very limited to what I can keep. Would I be able to do dual 175W or 150W Metal Halide or should I go to 250W? How much is too much? I've been looking at 48in Outer Orbit 2x150W 10K HQI-MH 1/ 2x130W Dual Actinic & 6 Lunar Lights. I've also looked at Aqua Medic Ocean Light T5/MH Combo Series, 48in 2 x 250W MH + 2 x 54W T5. Anyone have experience with either of these? I currently have some mushroom coral and a hammer coral.

[Entropy]

Do you have to have a complete unit or can you retrofit into an existing canopy? I would go with 2x175w metal halides with IceCap E ballasts and the new Iwasaki 20k bulbs and supplement it with either 2x110w VHO (preferred) or 2x54w T5 blue plus (2nd choice). You could probably get it done for under $500 for the retro.

[sharky71]

i have an existing 48 inch fixture which contains 2 65 Watt Power Compacts. Could I pull that stuff out and put in a retrofit? I've never done that before. Is there a link which explains how to retrofit?

[Entropy]

Chances are it will not go into another fixture. It would be more for a wood canopy type setup, unless your curren fixture is in a wood canopy.

[sharky71]

did you build your canopy and then install the retrofit kit?

[Don Berry]

250's are going to be overkill if you aren't interested in an sps tank. The AB 10K bulbs that come with the fixture will fry your soft corals. I run the same set up you are talking about on my 72 gl bow. It's perfect for an SPS tank though.

[sharky71]

would 2 175W and 2 110W VHO actinic be perfect or could I even go down to 150W MH? I could always place the higher demanding corals closer to the surface.

[Entropy]

I would go with the 175w versions over the 150 de. I just like the simplicity of SE bulbs better. You don't need to shield them and they just unscrew when you need to change them. Plus they are easy to clean if you need to.