If you’ve ever looked into a pristine reef tank, chances are the rock work was the first thing that caught your eye. Those jagged, porous structures appears as nothing more than a backdrop to the colorful fish and vibrant corals that demand attention. If you’re a new hobbyist, you most likely purchased your live rock because it had a catchy name or it look nice.
You expect it to look nice. You expect it to give your shrimp a few hiding spots. That’s a shallow way to look at what’s actualy going on in that aquarium.
So what does that mean? The truth is that live rock isn’t an ornamental addition to your tank. It’s a living filter that are far more complex than simply providing a place for corals or fish.
Understanding How Live Rock Supports Reef Tanks
Live Rock as a Living Filter
It do the heavy lifting needed to manage the biological waste created by your livestock. Without it, you’re fighting a losing battle against the biological waste produced by your livestock. You have to buy more equipment and hope it works.
When you understand how live rock work, everything about maintaining your tank change. Your attention move away from purchasing more hardware and towards growing existing ecosystem that exists within stone structures. Live rock immediately houses good bacteria.
The Role of Beneficial Bacteria
They’re the unsung heroes of nitrogen cycle; the microscopic critters that does the dirty work of converting toxins produced when you feed your fish and their waste builds up. Ammonia spikes in the water as soon as it is produce. It’s lethal to marine life in minutes.
Bacteria on the rock convert that deadly ammonia into nitrite. Then they converts that toxic substance into another less-toxic compound called nitrate. It never stop.
Biological Filtration and Cleanup Crew
A piece of plastic, like a sponge, does not have enough surface area or different type of surfaces to replicate biological filtration. That’s where the rock come into play. In addition, there is also healthy population of invertebrate life living inside or on the rock.
Often referred to as refugium organisms, tiny shrimp, snails, and crabs scavenge algae and waste that settles on the rocks surface. Not only do they clean up uneaten food before it rots but they also help control nuisance algae growth. By doing so, this natural cleanup crew reduce the workload on your mechanical filtration.
It also provide a layer of biological stability that no filter can offer. When you purchase live rock for your tank, you’re purchasing a self-cleaning service. Many people fail to understand that chemical makeup of the rock also affect things.
Chemical Stability and Mineral Release
For the most part, live rock is made up of calcium carbonate (aragonite). Because of this, it gradualy breaks down and releases both carbonate and calcium ions into the water. These is used to help keep the alkalinity and pH buffered so they stay at levels that are good for coral skeletal growth.
Not only does it maintain the water’s stability over time, but it decrease how often you have to dose supplements. The rock function as a slow-release mineral supplement. On the other hand, it will hold organics deep in its pores.
Managing Dissolved Organics and Flow
That’s where it gets tricky. Too much organic material held inside the rock can leads to a buildup of dissolved organics. Properly managed, the bacteria on the surface will breakdown waste, but the internal structure can act as a reservoir for dissolved organics.
That’s when you see the reference to deep sand beds or refugiums. Their purpose is to add to the role of the rock by dealing with various stages of waste processing. Make sure that water flows throughout your rock structure.
Areas where water does not move within the rock can create dead spots. These spots allows anaerobic bacteria to grow, which produce toxic sulfides that smell like rotten eggs. Preventing this is why good flow is important.
Curing Live Rock Before Use
Another key step in helping aquarists understand what’s realy on that live rock is curing the rock before placing it into a show tank. Most of the time, there will be some detritus and hitchhikers trapped in live rock during the harvest process. Placing cured or uncured live rock straight into your established tank can result in a huge die off and a following crash in water parameters.
By curing the rock, letting it sit in a separate system while the first round of decomposition finishes, you avoid this total tank crash. It will take weeks, but at least you wouldn’t of had to deal with a complete tank crash. It also teaches you about patience and how much of biological load you’re bringing in.
In the end, the key to a well-run reef lies in live rock. Live rock provides the ecosystem food, buffers it, and filters it, things no amount of mechanical gear ever will. Provide good flow, treat it with care, and let it do what it does best.
The healthy rock below your corals is the direct cause for their beauty. Once you realize this, that the rock is alive and functioning, you cease viewing it as a static part of the scenery. Instead, you begin viewing it as the heart of the tank.
