The first stage of planning for our new 180-gallon reef tank build is to buy some rock — a lot of rock! I’m thinking we’ll need 200 to 250 pounds. If we bought all live rock, we’d be out a pretty penny. So, my husband and I decided to purchase mostly base rock (dry rock that doesn’t have any live bacteria in it), then seed it with about 20 pounds of live rock. Over time, the base rock will develop the good bacteria we need for denitrification and eventually all the rock will become live. Base rock is considerable cheaper than live rock, but it will still be a big purchase.
The reason we’re buying the rock first is we’re planning on “cooking” it. No, we’re not going to boil the rock and serve it up for dinner. Cooking refers to the process of placing the rock in a dark, warm, oxygenated environment and allowing it sit for many weeks or months (doing weekly water changes). After time, all the organic material is “cooked” off the rock (i.e., the bacteria destroys it) and phosphates are purged from the rock. Phosphates in your system lead to algae, so you want to remove as much as possible before putting rocks in your tank. You know the rocks are ready when a phosphate test of the water reads zero.
This could take anywhere from six to 12 weeks (or even longer), so we’re going to do this first — before we even purchase the tank itself. This is going to be a big system, and I really want to do it right from the beginning to help prevent problems in the long run. As soon as our “rock kitchen” is up and running, I’ll be sure to post pictures and let you know how it’s progressing.