We use six 400w fixtures over one of the 4'x8' coral beds and six 250w over the other 4'x8' bed.

You can barely notice the brightness difference but that may be because our tanks are only 13" tall. :lol:

Not sure if this fixture is what your looking for but I'll throw it out there.
I have a Current 24" 250 hqi fixture with 4 x t5 bulbs and led moonlights.
All the bulbs were replaced early this year and I also have a brand new Phoenix 14,000k bulb. Let me know if your interested

Attachment 13022

Probably one of the better options, and a good bulb.

Thanks for the offer Dave!

I'm still researching and am a little ways away from pulling the trigger on anything, but I may just message you and see if you still have it when it comes time to commit to something.

I'm a huge fan of combo fixtures too and that one davej has looks AWSOME and is one I would use. In fact, when I started I had their 48" model and loved it! Now I have a 72" combo fixture :-)

I like T5s on a 36" tank. That's what I have on my 50 (36x18x18") and it does quite well. It has everything from softies to SPS in it.

Just a heads up if you were leaning towards my light.
It has been sold.

I have a fixture that has two 250w MH and 2 actinic t5s
my tank is 4 feet and i think 20 inches tall. I like the combination and wattage. MHs get hot and 2 400w on your tank will be more light than you need I think. :idea:

I have a metal halide fixture and a t5 retro coming in as we speak. I plan to run a 250w radium on my pfo hqi ballast with two t5 and two 12" diy rapid led strips both with royal blue and 410nm uv. Should be a nice mix using all three light styles and my tank is 30x24x24

ok, I am going to go a bit different, by not recommending 250 or 400, but rather find a bulb you like the look of first.

with the reflectors now days both will give you almost the spread you need, but if you have nothing on the sides then you don't need 36" coverage.

but seriously at 18" tall you don't need 400watts, the only reason to go to a 400 watt fixture would be if you like the look of the radium bulb, and even then you can have a darker radium or a lighter radium depending on if you run it on a normal 400 watt MH ballast or a sun agro ballast which used to be incorrectly called a 400 watt HQI ballast

my personal favorite was the Aqualine Buschke 250 watt 10K , but it is a SE bulb. I think it could be got in DE but the SE had a higher output. combine this with two URI super actinic VHO bulbs and you had a beautiful ice white color with lots of pop. weather you not you can still get these bulbs in Canada or not I don't know.

Start by looking at pictures of MH lit tanks and see what there using for there lighting equipment, find a look you like and go that way for bulb and equipment.

Steve