we have a 120 gallon reef tank with a 3-4 inch deep sand bed. We have had it for about 3+ years now and over the past few months we are having really bad algae issues. We have hair algae growing over large portions of rock along with cyno and also a very strange dark green almost black looking velvety algae growing on one side of the tank sand bed. It appears our water levels are all looking alright but we cant figure out why now all of a sudden we are being plagued with all these diff types of algaes. We currently only have 3 penguins on the tank and a magnum 350. 180 pounds of rock and probably the same or more in sand. lots of softies and one little nemo running around;) Any ideas how we can get our tank back? Also does anyone know of a really good magnet to clean the glass with for 1/2 inch glass the little magfloats just dont seem to do the job.