You can try using Aqua Vitro 8.4 buffer. My wife had some non reef rock in her tank that was leaching silicates into her tank, unfortunately the rock was also covered in corals :( Her glass would literally look like brown tinted glass. But, we starting dosing the 8.4 and within two days her glass was clear and clean. It also raises your alkilinity, which is good. I just would moderate it's use because we noticed that using it daily caused an outbreak of cyanobacteria which is always present but usually under control. It does work well though.....
