Does anyone know if all PFS is silica sand ? I've heard that silica can cause brown algea issue's if it introduced into a tank ... I have PFS now and continously get brown algea on it no matter what I do.... And I'm gonna be setting up a 300gallon I don't wanna have the same issue's... And yes I like my white sand... I want white sand that won't cloud the water when a fish swats its tail but I also don't want brown algea all over my white PFS.... Thought bout mixing white play sand with the 100lbs I already use/have in my 140gallon, what do you guys suggest or think ?