So dear readers… Apparently hermit crabs require two kinds of water. Not prefer. Not occasionally enjoy. Require. Which honestly surprised me because before this journey, my knowledge of hermit crabs was approximately: “Tiny beach creatures with commitment issues regarding shells.”

Now here I am researching aquatic chemistry like I am preparing a crustacean for a tiny spa retreat. Because it turns out hermit crabs need both fresh water and saltwater to survive. And not in a dramatic “optional wellness trend” kind of way. In a very real: “If you do not provide both, your crabs can become sick or die” kind of way.

Which naturally sent me tumbling deeper into the endless rabbit hole that is hermit crab care. Because once again, these little creatures are far more complex than people realize. Hermit crabs are terrestrial, meaning they live on land, but they still rely heavily on water for almost every important bodily function.

Breathing.
Hydration.
Mineral balance.
Molting.
Basically existing.

Which is honestly impressive for tiny armored raisins carrying homes on their backs. Now let us discuss the salty side of this tiny crustacean lifestyle.

Why do Hermit Crabs need saltwater, you may ask? One of the most fascinating things I learned is that hermit crabs do not breathe the way we do. They have modified gills. Not lungs.

Gills.

Which means those gills have to remain moist in order for the crab to breathe properly. And somehow these tiny creatures manage this by carrying water inside their shells like little portable humidifiers. Nature is wild. The saltwater helps them maintain the proper salinity levels inside that stored shell water, preventing it from evaporating too quickly and helping support healthy respiration.

Which means yes… My tiny shell goblins are essentially carrying around customized internal climate-control systems. As one does. But saltwater is not just about breathing. Marine saltwater also contains important minerals and electrolytes like calcium and magnesium that hermit crabs need for healthy body function, shell maintenance, and overall health.

And when it comes time to molt? Oh, they become little saltwater fanatics. Hermit crabs preparing to shed their exoskeletons will often drink and bathe heavily in saltwater to help prepare their bodies for the exhausting process of molting and growing.

Which honestly sounds stressful enough that I might also require a salt bath afterward.

Why do Hermit Crabs Need Freshwater too? Now while saltwater is essential, freshwater is equally important. Hermit crabs rely on dechlorinated freshwater for drinking and hydration. And yes. It must be dechlorinated. Because apparently these tiny creatures are more sensitive than I am after accidentally using the wrong shampoo.

Tap water can contain chlorine and chloramines that are harmful to hermit crabs, so the water has to be treated with a safe dechlorinator before use. Freshwater also acts as a rinse for them, helping clean away waste, dirt, and excess salt buildup from their legs and bodies.

Basically:

• Saltwater for minerals and respiration.
• Freshwater for drinking and cleanup.

A tiny crustacean balance. Like a very dramatic skincare routine.

Now lets get into the tiny crab pools! Now according to hermit crab care guidelines, they should always have access to both fresh and saltwater pools deep enough for them to enter freely if they choose. And this… This is where things got dangerous for my wallet. Because while researching water dishes, I accidentally discovered the world of hermit crab pools.

And dear readers… Some people are out here building crab waterparks. I am talking elaborate little pools with ramps, rocks, bubblers, waterfalls, bridges, and filtered systems. Some are simple. Others look like luxury tropical resorts.

And honestly? I understand the temptation. Some crab owners add bubblers to help prevent stagnant water, extend the time between water changes, and provide enrichment for the crabs. Which means somewhere out there, hermit crabs are literally sitting beside bubbling spa pools while I continue paying bills like a peasant.

Do not misunderstand me. I have absolutely been eyeing those fancy pools. The dangerous part is that my brain has now started whispering: “You could probably make one…”

And now I find myself wondering if anyone I know owns a 3D printer. Because clearly the logical next step after buying hermit crabs is apparently becoming an amateur aquatic architect. This is how it begins.

First it is:
“Oh look, tiny water bowls.”

Then suddenly:
“What if they had a two-level pool system with built-in bubblers and textured climbing ramps?”

I fear there is no saving me now. At this point I fully accept that I am becoming one of those people who casually discusses humidity percentages and marine salt brands with alarming passion. And… I regret nothing.

Because despite all the chaos, all the research, all the spiraling, there is something oddly beautiful about learning how complex these tiny creatures really are. People see hermit crabs and assume they are simple.

Disposable.
Easy.
Low maintenance.

But the deeper I dive into their care, the more I realize how much they truly need to survive and thrive. And maybe that is part of why I have become so attached to them already. Tiny creatures carrying entire oceans inside borrowed shells. Trying their best to survive in a world that rarely understands what they actually need.

Honestly?

Relatable.

—Bella Imperia

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