About a year ago I accidentally dumped over 600+ mL of two-part alkalinity solution into my reef, which proceeded to turn solid white for two days (thankfully nothing was lost). Shortly afterward I noticed most of my sandbed hardened into big chunks. About 4 months ago I replaced the sand. Now it has hardened again! I've been working on lowering my salinity, which is now at around 1.028. It's been working down from 1.030++ (bad refractometer calibration solution).
Could the high salinity cause this problem?