It is very important to have the correct amount of live rock. Some people have gotten carried away with the idea that if some is good, more must be better. This is not true! As with all concepts of reef keeping, balance is very important here. If you don’t have enough live rock, natural internal filtration will be ineffective, because the bacterial colony on the rock will be inadequate to perform the task. Or, if you have too much live rock, you will have dead spots on it. These are areas of live rock that are covered with other rock, blocking some surfaces from light and water circulation. These dead spots are likely to trap waste, sediment, uneaten food, and many other products you would otherwise remove regularly. When waste products accumulate in these areas, they will be a sure food source for micro-algae, which will thrive, causing diminished water quality.
This is referred to as “stacking” the rock, and it should be avoided at all costs.
The correct amount of live rock to have in a reef tank is between a minimum of 1 pound per gallon and a maximum of 1.75 pounds per gallon. Somewhere in the middle, like 1.35 pounds per gallon, would be ideal. Do not exceed 1.75, unless you want to turn some quality live rock into base rock, which would take at least a year to recover and resemble what it was before other rock was stacked on top of it.
I have met many people who have jammed as much live rock into their tanks as would physically fit, in an effort to create a natural system. The only result they got was a natural disaster. Two-thirds of the rock died. The water had so much nutrient in it that it could not be reused. They had to start all over again, rinsing all the rock, buying another tank to use the excess rock, or trying to sell the rock back to the store (as base rock). They learned that when it comes to amounts of live rock, more is definitely not better. Again, do not exceed 1.75 pounds per gallon.
Amounts and quality of live rock for a 55-gallon setup: (55 gallons x 1.5 = 82.5 lbs.)
- 12 lbs. base rock for bottom, fist size
- 40 lbs. premium quality for back and sides, large flat
- 20 lbs. encrusted octocoral, large long, for high points
- 11 lbs. of ricordia mushroom rock for accents
