Transforming an ordinary aquarium into a captivating underwater world is possible, and it starts with replicating the caves and crevices you find in nature. These features are essential for fish: they provide not only hiding places but also definite territories within the environment. With my latest project, I contributed to a blog where I share my experiences as well as tips and insights that help designers create dynamic environments mimicking these niches in nature. In this segment, I will outline some basic techniques for designing and maintaining the water passage niches known as “caves” or “grottos.” They indeed are some of the most engaging features one can include in an aquascape, something both visually stimulating and aided by unique biological interactions involving your fish.
For successful and aesthetic underwater cave habitats, it is crucial to choose the right materials. Aquascapers often use native rocks found in their local environments, mostly because those work best for their climate (temperature and humidity), as well as for how they look. Some popular stone choices are Seiryu Stone, Dragon Stone, and Lava Rock, each known for its unique beauty and natural appearance aesthetics that surely play a huge role in why many aquascapers opt for these particular stones when building underwater formations.
From my experience so far, I can tell you with confidence that building an intricate rock formation warren or “cave system” without the use of some sort of adhesive is next to impossible. Seiryu Stone seals into place by itself because of its special texture, the same reason it creates spectacular visuals when used in an underwater habitat situation. —Toby Scroggin
It is crucial to prepare rocks for your aquarium safely and correctly. Doing so will guarantee the health of your fish and other tank inhabitants.
Ensure that dirty rocks are free of dirt, partially buried in a bucket filled with water, and left undisturbed (not stirred) for several days or weeks. Then thoroughly brush the rocks on both sides (using a stiff-bristled brush works best), covering every part to remove any residue from their faces. Work toward getting all particles off the surface; otherwise, they may somehow harm your fish when you put them in the tank. Cleaned rocks can be placed in a bucket and allowed to sit at room temperature while COVERED for four days as part of killing any pathogens that might have made their home inside Anastasia State Park and Friend Lake Recreation Area rock during procurement. Rinse all. Follow with a pH water test after placing prepared rocks into a new bucket to make certain changes, if any, aren’t significant—significant being defined as anything beyond what’s considered “safe” by most aquarium keepers or within 0.5 pH units either way from the current reading).
Designing an underwater world with caves and crevices requires close attention to detail and wise arrangement of rocks. You’re not just placing rocks anywhere you’re creating a space that’s meant to look like it could be found in nature, deep down or near the surface. The way the design holds together – or doesn’t – is what makes an aquascape good or bad. A placement error can make your whole arrangement feel off-kilter, like a painting that’s been hung incorrectly on a wall. And speaking of walls, the bigger rocks in your design should serve as focal points; otherwise, everything feels top-heavy and dull.
You want some visual interest; you want some lead-in lines that carry the eye around your aquarium; you want Smithsonian-horstenseliae (that’s “decoration” for those without Latin).
The successful setup of a cave and crevice aquascape relies both on the natural appearance of the structures and their ability to provide fish with shelter and territory. It’s crucial that the rocks are securely positioned so they don’t shift, fall over, or bury themselves in the substrate. If necessary, you can use aquarium-safe adhesives or epoxy to glue rocks together, but use these binders sparingly, as too much can be dangerous for aquarium inhabitants.
For submerged caves (that is, caves under water), you may need to do some creative stacking and interlocking of rocks to get them to remain upright and stable. For both submerged and emergent (above water) caves, try to create a naturally varied appearance by using a combination of sizes, shapes, and textures of rocks—rather than relying solely on straight lines or symmetrical patterns that would make your carved-out rock formations look like nothing more than so many modules.
The natural beauty and functionality of your cave and crevice aquascape rely heavily on the roles that plants and fish play within it. Most everyone knows that adding plants to an aquarium can create a visual refuge for both the fish swimming above and those darting in and out of the numerous hideouts created by both plants and rocks. Indeed, some of the most fascinating moments in observing an aquarium happen when a curious fish darts into what seems like a very confined space only to emerge a few seconds later with seemingly enough time to spare.
The fish and invertebrates one chooses should work together with the layout of the cave and crevices to create a harmonious community within the tank. That’s all well and good, except when it comes to putting many species together. Then things can get really tricky, as their totally different demands for water quality, temperature, and swimming room can lead to disaster if not carefully thought through.
Take dwarf cichlids like Apistogramma spp.—they’re great for life in a communal tank Harris would be proud of, or Pelvicachromis corrusca from West Africa. Those are ideal for working into your community because both are highly motivated territorialists that stake out all sorts of crazy shapes in sand or rock that your top-damming Plecostochlorobius plecostomus nosferatu will use once things warm up.
It is very important to keep up with regular maintenance if you want your pristine aquascape of a cave and crevices to continue looking good and remain healthy for your fish and plants. Maintaining good water quality is just too crucial not to mention, so I dally as little as possible around the watery environment while tending to its innards. My walking life outside of work is becoming less frenetic now that I’ve found some pacing in doing consistent everyday workouts. Regular maintenance keeps those pesky water UNCT (unclean climate habitat, toy municipality, top-notch test kits) parameters stable and safe for my UFA proxies (Ultra Freshwater Aquarium proxies).
Cave and crevice aquascapes with plants can easily develop into thriving, diverse ecosystems. Part of the secret to their success is regular trimming and pruning. These help maintain both the appearance and health of the plants in any given space.
Trimming dead or overgrown leaves from epiphytic plants, like Java ferns or Anubias (a type of moss that ships with many aquascaping setups), keeps things tidy. Pruning also helps control carpet plants so they lay as close to the “ground” as possible, again maintaining appearances. In my setup, I trim 1-2 inches off both sides of my Java fern every few weeks. This keeps it from overshadowing my rocks while it continues to grow otherwise healthily.
Ultimately then, regulating plant growth through not-so-fun tasks like pruning makes for a much more interesting-looking community without excessive vegetation that would shade various inhabitants in your water garden, including the fish!
In cave and crevice aquascapes, algae may prove a pesky and persistent problem due to the very nature of these types of ecosystems. That being said, it really is a common issue plaguing many aquaria housing such communities. The first step in any anti-algae endeavor has to be lighting.
Of course, this also holds true for maintaining an equilibrium between proper light intensities and durations on the one hand and the balance of nutrients that have to be maintained for the benefit of plants (specifically photosynthesis) on the other. Spots with too much light tend to develop algae; spots with too little do not usually experience this serious aquatic health issue. Balance is everything: too much food leads to unhealthy conditions favoring excessive plant growth (a classic “boom-bust” cycle), which grows algae when there isn’t enough light for the plants; not enough food starves aquatic life, leading directly toward an escalating health crisis among all community members from top to bottom, a situation that never ends well.
Lighting issues notwithstanding, I think what makes cave and crevice aquascapes unique are their particular physical characteristics that can either encourage or deter algae growth. Working together to establish healthy aquariums and preventing potential crises involves careful management of lighting and nutrition—ensuring stable environments through controlled light intensity and duration, thereby combating negative trends associated with aquarium decline.
It is both rewarding and creative to replicate the underwater caves and crevices that you find in rock formations, bringing them home with you. You are now the master of your own miniature world, filled with the swimmer-class fish and lively community fish that make up your aquascape. Each plant has its own unique need, just like each of us does. Whether they’re divers or sprawlers, plants must have water; otherwise, they’ll fasten open leaves to the surface and send out search parties for a pathway up into the atmosphere.
Plants need light; again, different kinds demand different quantities some ridiculously high amounts in my book—in order to carry out photosynthesis. They also need a certain range of temperatures (don’t put an Edema on a hot plate!), CO2 (a critical gas), and some amount of fertilizer—although too much can be toxic.
You’ve got to introduce new fish slowly; there’s no rush. Ease them past each other during introduction, that is called “suction,” which actually prevents harm from an unchecked face-to-face confrontation by two cultivars at once in limited space while allowing what I consider to be two mostly peaceable communities to coexist inside your tank after enough time has elapsed for slow introduction during setup.
