It's a terrible gauge though, IMO
. 100 watts of power compacts has no where near the intensity that 100 watts of individually reflected T5s has. And don't forget about LEDs which are even more efficient per watt. If the OP has a very tall tank and very little live rock, The anemone may not have enough real estate to climb.
Bottom line is, the dimensions of the tank and distance from the bulb is very important when deciding what light to buy.
I went to a guys house and helped him with his tank the other day. He had 2 x 250 watt metal halides over a 75 gallon tank. he had them mounted so high above the tank that the PAR reading on the sand bed was barely 25.
he had no shortage of watts, but his sps
was all brown.