tunze in sump protein skimmer

[genzod66]

have a 120 f. o. tank been set up for about a month,my skimmer is sending tons of micro bubbles into tank,i guess their isnt enough bio load only have 3 small clowns and a tang,how long til i can turn the skimmer on without getting the bubbles,its been broken in???lfs said tunze says needs more bio load,liquid is clear,no skim??