I have a 90 gallon tank and a trigger 36 sump. Total water volume is about 100 gallons including displacement from rock and sand. My refugium section will only hold about 7.4 gallons. Currently I have a basketball sized ball of chaeto and I run carbon and gfo in a dual reactor. Since I do not have the required 10% refugium should I avoid the core 7 and go with other methods? My tank is about 8 months old.