I would say I have about 75 lbs of rock. Tank is 7 months old for me, but transferred from someone elses home with sand kept as minimally disturbed as possible.
LR was mostly there, but I have added some.
I should mention I have a clam, if that makes a difference.
Oh and I keep SPS and LPS.
Parameters are good, although Nitrates can fluctuate between 10-20 ppm.