I just changed the light over my 20 gallon from a 65 watt 6700k CF to a 70 watt 10000k hqi. Right away my tank started pearling like crazy where there was very little before and the few bubbles I had came late in the photoperiod. I'm keeping the same nutrient levels (25-30ppm NO3 & .5-1ppm PO4) and CO2 is at 30 ppm but I'm noticing thread algae starting to form. Would this indicate my 11hr photoperiod needs to be reduced? Maybe try 8 or 9hrs. for a while?