When most people assemble an aquarium, they are presented with the issue of substrate. They can go the traditional route of an aragonite based sand, which give what most would call a more natural look. Unfortunately, that route often leads to the accumulation of detritus due to having to use less water flow to prevent sandstorms throughout the tank. To combat this, hobbyists could go with a bare bottom tank, removing all the sand in favor of being able to achieve higher rates of water flow. While this is great for those seeking better nutrient control, it looks artificial and limits the type of livestock that can be housed. But there is another option, thanks to some out-of-the-box thinking by aquarium industry expert, Scott Fellman.
In a recent posting on his company’s Reef2Reef forum, Scott offers up the idea that instead of sand or going totally bare bottom, hobbyists can line the bottom of their tanks with rock rubble. This provides a great habitat for small invertebrates to thrive, while also giving the tank a somewhat natural look and allowing hobbyists to ramp up the water flow.
An added benefit to this type of hardbottom substrate is that it can act as its own frag station. If a coral falls off a rock and lands in the rocks, or reproduces like a Pocillopora, then all of those rubble pieces in the bottom will act like frag plugs. Just take the rock out and toss another one into its place. It prevents you from having to hack up coral colonies.
So, if you’re debating between between sand or bare bottom, don’t count out the rocky bottom look.