[rmlevasseur]

Many people will tell you that they buy LR based on shape and porosity alone, and I am in that camp. For this I don't think Marco can be beat. The process of "cooking" involves putting your LR in a tub, in total darkness, with heavy skimming and water changes. The idea is that the bacteria will survive, and eventually start consuming any organic matter on the rock that may contain phosphate and/or other nasties. Everything on the rock dies except the bacteria. But, you are ultimately rewarded with algae-free rock and lower tank phosphates. The bacteria is still there to repopulate, and coralline eventually comes back.

I attempted this process with my rock, but I sure wish I had purchased it months sooner. I think my time was effective, based on what I am seeing now, but ultimately I wish I could have done it for 4-5 months. It is my plan to buy an additional 1/3 of LR for my tank, and constantly cycle 1/3 of the display tank live rock into the cooking tubs.

Since I couldn't cook my Marco as long as I had hoped, I did give it 4 days in a strong muriatic bath before starting the cook process. I think this did help tremendously, as the waste water was almost black. When cooking dead rock, you have to add some LR to the tub to introduce the bacteria needed to "eat" away the organics.