MARINE ROCKS

Clean, porous dry rock is the best starting point for most reef tanks, because it gives beneficial bacteria plenty of surface area without bringing in pests. Marco Rocks are mined in Florida, washed and 100% free of pests and nuisance algae. Genuine Fiji Pukani Rocks are extremely porous, giving them outstanding biological filtration capacity for demanding reef systems.

Dry rock is the safer choice for most new reef tanks, because it carries no pests, aiptasia or nuisance algae. The trade-off is that it starts without bacteria, so the tank needs to cycle before you add livestock. Over the following months coralline algae and beneficial organisms colonize the rock, and it becomes live rock on its own.

Marco Rocks come in three styles. Foundation rock forms the base and main structure, Shelf Rock creates flat ledges and overhangs for placing corals, and Basic Reef Saver is the budget option for filling out the base. Each style is also available as Marco Rocks Coralline, and Nano Shelf Rock comes in a 3.5 kg bag for small tanks.

A common starting point is about 0.5 to 1 lb of dry rock per gallon of display volume, depending on how open you want the aquascape. Very porous rock like Fiji Pukani is lighter for its size, so it goes further per pound. Leave open sand areas and swimming space; more rock is not always better for flow.

Use E-Marco Cement, available in gray or coralline color, to build strong joints for arches, pillars and larger structures, and follow its curing directions before the rock goes into water. For quick bonds, many reefers combine Marco Rocks Aquascaping Powder with Instant Hold Aquascaping Glue. Marco Rocks Coralline Colorant helps cement joints blend into the rock.

Some can, at first. Because Fiji Pukani comes from an ancient marine reef environment, it may release small amounts of naturally bound phosphate during the first few months underwater. This is normal and settles down with regular water changes and phosphate control. Mined Marco Rocks are washed and ready to use.

Marco Rocks are $3.75 per lb for Basic Reef Saver, $4.85 per lb for Foundation and $6.85 per lb for Shelf Rock, with Marco Rocks Coralline from $4.29 to $7.99 per lb. Genuine Fiji Pukani Rocks are $71.90 for a 10 lb mix or $287.68 for a 40 lb box. E-Marco Cement is $32.99 per 2.2 kg bucket, Marco Rocks Aquascaping Powder is $15.35 and Bahama Aragonite Sand is $55 per 10 kg bag.