Agreed. I like MH lights. I have a 150watt over a 30gal. I've read that you should have 4-5 watts per gal. So for a 90gal your looking at 450 atleast. Depending on how long the tank, I'd go with 3 150watt MH or 2 250 watt.IMO
You could use that light for your setup and it will work. Depending on what kind of corals you wanted to keep you might need more wattage. You could start with that light and then if you needed more watts you can add another light to use in conjuntion with that light. I'm sure there are people here that use both PC and MH lights together. I'm a fan of MH lights. To replace the bulbs are cheaper. My light has one MH. Thats 1 bulb to buy. But PC's have 2 or more bulbs to buy. Like the one you have, has 4 bulbs. The pc bulbs are 30-50 bucks a pc. The same for MH but not as many bulbs. Plus I like the light it gives off. JMO
I am a bit concerned since I don't just do things in small steps
Do they come in like 125 watt bulbs for this kind of light?
and is this lunar light something to need?
I was a total aquarium newbie a year ago
and now I am about to hit 600 gallons in my 13th month (officially yesterday) of this hobby ...
depends on corals you want to keep. i have a 55 gallon and i have 400 watts of pc lighting. and no you cant just change the bulbs, unless the ballast says they are rated for higher wattage. i dont think you should run out and but mh lighting if this is you first sw/reef tank. you should start out with something easy like shrooms or zoanthids etc.. any softie really. you could just try it with the light and if it doesn't look like its working you can move the corals up in the tank closer to the light until you get better lighting.