Well the tank is new to my house (4-5 months) but sand and rocks came from the same tank and it had been running for years before... Rocks never dried out were always in water at temp and being circulated so I would think the tank is definitely more mature then the 4-5 months that I have had it...
I had dirty sand at a point but it bugged the crap out of me so I got some cleaners and a sifting gobie and they cleaned the sand up within a month and they keep it clean now...
