[Doug]

I recieved my 400 watt 20K yesterday. Fired it over the empty 170. Very nice light. Brighter than my 12K, even to my eyes and thats with a normal PFO ballast.

But I would say, even thought its brighter, like the 12K,s, its still not bright enough,{on a normal ballast}, to light the 48 inch by 32 inch tank alone.

As the 170 is going to house mostly lps & mushrooms it may be enough for them, but my large leather may not like it. I was going to leave it in the 180, but its only going to be sps and various anemone polyps.