I think of starting to get cyano, its looks really dark red in some spots in my sand bed, I have a mag7 running on a 55gal. I just added some live sand but I dont think this would cause a problem or would it? I do water changes every week, I think a mag 7 is enough flow correct? My phosphates are a little high which I dont understand its 1.5. I use RO/di water and my tds meter shows a 6 which im thinking i may have to change the DI resin.