[cheeks69]

I never liked this rule and never really followed it. I think there's alot of negatives by keeping a large amount of rock in the tank like poor flow, detritus accumulation within the rocks, lack of swimming space etc.

I have about 65 lbs. of LR in my 93 gal tank and 15 lbs. in my 21 gallon sump and still think it's too much especially as the SPS corals continue to grow. I do have a DSB so I have plenty of surface area for aerobic/anaerobic bacteria. This of course will be different if you have a SSB or BB tank, you'd need considerably more rock but nowhere near the amount usually recomended especially if it's the porous Indo-Pacific rock.