How we make a Hollow
01 Every Hollow begins as a design, but the first design is never the final one.
We turn ideas into physical prototypes, working on proportions, entrances, internal geometry, wall thickness and the way the cave fits into an enclosure.
Once we’re happy with how it looks, the real testing begins.
02 We test our products where they’re actually meant to be used: real aquariums and terrariums.
What’s the point of a decoration if you only keep it for a few weeks because it’s poorly designed or too hard to maintain?
That’s why we test for the things that only become obvious with time: how easy it is to clean, how substrate and debris build up, how water flows through it, how accessible it remains, how naturally it integrates, and generally how it holds up to everyday maintenance.
03 We design every Hollow to disappear into the enclosure.
Shape, slopes, texture, and the way the surface interacts with light are all engineered to help each Hollow blend naturally with plants, rocks, wood and substrate.
Our goal is simple: if you barely notice the Hollow, we’ve done our job. We want the natural elements to shine.
04 Looking good on day one is easy. We care about day 300.
Aquariums develop algae, biofilm and detritus. Substrate finds its way into every gap, and some decorations quickly become a pain to keep clean. In terrariums, maintenance is different: a cave can usually be removed, cleaned and put straight back.
We design and test with both realities in mind.
We actually use our products in our own setups. In aquariums, we pay particular attention to debris buildup, inaccessible areas and water flow. In terrariums, we make sure the cave remains simple to remove, clean and reposition without turning routine maintenance into a chore.
If something becomes frustrating in everyday use, we find out why and improve it.
05 Most problems only appear with time. We build our caves to last for years.
That’s why we’re comfortable offering a 2-year warranty.
We keep prototypes in our own setups long after the initial testing is finished. Months of actual use reveal things a short test simply can’t: where dirt builds up, which areas become harder to clean, how the material ages, whether it can support significant weight without deforming, and whether the design remains as practical as it was on day one.
It’s easy to create a good-looking cave. It’s much harder to create one that isn’t a chore to maintain.
06 Our first designs always reveal things we can improve. That’s why iteration is necessary.
Aquariums and terrariums are complex little ecosystems, and especially underwater, no initial design can account for every issue that might appear over time.
Testing exposes things we couldn’t see during the design process. An entrance might need adjusting. An internal corner might be difficult to clean. A slope might not sit naturally beneath the substrate. Flow might not behave the way we expected.
So we change it, make another prototype and put it back into a real setup.
We’re no magicians. We simply found that the best way to make a great product is to test it, use it and improve it over time.
We use our products just like you would, and that’s what makes us different.
We keep doing that until we’re happy putting our name on them. We use what we learn and apply it to every product.
Let’s use The Corner Hollow as an example.
Dozens of prototypes. Five aquariums. Years of combined testing. Our bestseller.
During its development, we had around five different aquariums running at the same time, each containing a slightly different improved version of the cave.
Slightly different shapes. Different entrances. Different internal geometries. Small changes designed to improve integration, water flow, accessibility or cleaning.
Instead of replacing one prototype with another and forgetting about the previous version, having several generations running simultaneously allowed us to compare them side by side over time, in real aquariums.
We lived with them. We aquascaped around them. We watched them accumulate algae and debris. We cleaned them. We discovered what worked and, more importantly, what didn’t.
Every problem was fixed and fed into the next version.
5 AQUARIUMS
DOZENS OF PROTOTYPES
2 YEARS OF COMBINED TESTING
In real aquariums. Low tech. High Tech. Inert gravel. Aqua Soil. Low light. High light.
And eventually, all those small improvements became the Corner Hollow we sell today: our best-selling Hollow.
But the testing didn’t stop when we started selling it. To this day, we still run two aquariums with Corner Hollows, and we keep learning from them and improving the design whenever we find something worth changing.
