[fishytime]

First off I wanna say that I am not by any means lumping all dry rock into the same category here....all dry rock is not equal, I believe some of it can come back to be being as good as live rock, but I dont think that Marco rock is one of the ones that can..it is rock that has been buried underground for a million years and is for all intents and purposes, petrified.....it is extremely dense and heavy....for the most part, the pieces you find, feel like a chunk of concrete when you pick them up(and they might as well be concrete)....every so often you will find a porous piece (relatively speaking) mixed in there but they are few and far between...Ive personally handled probably about 3000 lbs of the stuff.....while the dense pieces are full of holes, all these holes are, is surface area.....the holes are almost solid and smooth.....good live rock is like a sponge, porous to the core, becoming "live" all the way through.....to give you an example, about a year and a half back, we got in a REALLY nice shipment of LR from Walt Smith....one of the pieces was the size of a bucket of salt and weighed 22 lbs when we first unpacked it.....one week later I sold it to a customer and it weighed 25 lbs....that piece soaked up three pounds of water in one week.....








Im willing to bet that a 22 lb piece of Marco rock, will be a fraction of the size and will still be a 22lb rock after ten years under water.... if you've ever tried to drill a hole through Marco rock or cut it with a dremel, you will have found that it is extremely hard and shatters easily....


my beef isnt really with Marco rock....it is more to do with the fact that Marco rock is marketed as cost effective, pest free, will be as good as live rock in a month solution to expensive "real" live rock....people need to treat it as base rock that just so happens to look like live rock.....they need to have in their minds from the get go that if you have a 200g tank that has 150lbs of Marco and 50 lbs LR, then you can not treat the tank as though you have 200lbs of rock....cuz they dont.....they have 50 lbs of live rock and 150 lbs of rock that may take as much as a year to become half as good as 150lbs of live rock (biologically speaking).....they need to go slow(er) and stock their tanks accordingly..... in the six years Ive been working at a LFS Ive noticed a distinct trend....that being, that people that have used Marco rock seem to have way more problems associated poor biological capacity (such as cyano, diatoms, high nitrates, high phosphates and general coral ****edoffedness) than people that have used LR......over the years, the "did you use any dry rock in the tank" question went from being one of the last questions I asked, to one of the first questions I ask when a customer comes in with fishues.....