The power of the light @ 360 watts ( HO ) total seems OK, but I think there are other problems with it.
The reflectors will not be designed for light penetration.
Without a splash lens, it's dangerous, and corrosion is a real problem with salt water. Unless it were mounted really high, to avoid water, thus limiting the lights power even more, corrosion will eat it up quickly, inside and out. IME/IMO, it wouldn't last more than 2 years, mounted above a tank, being a fire hazard the whole time.
Also, it says the bulbs are 51 watt. 4' T5HO bulbs are normally 54 watt. 6x51=306, not 360.
You may have an issue finding bulbs in the correct color temperature for an aquarium as well.
With all these factors considered, you should be able to find a T5 HO unit designed for aquariums, for $20-40 dollars more than this one.
Just my opinion, but I wouldn't do it. Best of luck!