can you help please

Question
hello this is my first post. I have just got myself the aqua medic percula 90 i have just filled today and powered her up i havent put the salt in yet as i am waiting for my temperiture to rise to the correct level .After half hour or so fiddling about with the skimmer i think i got it set right will this fluctuate when i add the salt? Also there is a slight humming comeing off the skimmer sounds like the motor is this normal as i can hear this sound above my trickle filter i have also changed the light to a arcadia 4 series 250 watt plus 2x T5 24 watt atinics is this suitable to keep certain soft corals and anemones would be greatfull for any advice thanks steve

Answer
the skimmer will change when you add salt, this is due to saltwater being denser than fresh and also the bubbles will be much smaller than they are in fresh water. the hum is normal, some skimmers are seriously noisy!

the lights sound fine to keep hard and soft corals, i would stay away from nennies, they have a very poor captive survival rate.