I have a 10 gallon nano. Just a few weeks ago,my tank was doing well. Now most of my corals are stunted & my frogspawn actually looks dead. I clean off the light each day & have just begun to dose 1 /4 tsp. of Kent daily.I do a water change once a week, trim the dead off the plants, fertilize them, & clean the glass inside & out. I leave my light on 8 hrs./ day. Any suggestions?