I live in the country and cant get help from the one pet store around here.i told them I keep getting redish purpleish stuff on my sand bed.they sold me chemiclean and it isn't working.its also going on my glass and decorations.i clean the glass and stir up the sand and it comes back on the sand.i have a 75 gallon community tank and everything always tests great.its been running 14 months and do a 10% water change every 2 weeks.my water is always clear so I don't no what im doing wrong.