Paludarium 2: Tragedy Boogaloo

It’s the end of an era, and by era I mean a handful of months of trying something new and watching it not quite work. Today, I officially lay my paludarium ambitions to rest for the foreseeable future. It was okay while it lasted, but the test did not yield the desired results and it is over. I am pivoting.

So, what happened?

A few months ago, I built an enclosure for soil to place within a specific aquarium, turning that aquarium into a paludarium. This enclosure was made of leftover material from previous projects and whatever odds and ends I needed to purchase to make it happen, then filled with potting soil and moisture-tolerant plants. The design was optimized to maximize the available water area while still having the largest land area I could build with the available materials, and while it was working, it was beautiful. I added isopods and springtails to make it bioactive and I explored numerous options for making it the best possible version of itself. Full of plants and light, with tannin-yellow water beneath and a limb-mounted orchid for tropical flair, it stole the show from behind me in so many Zoom meetings and impressed visitors and viewers alike. It faced numerous challenges getting even that far, but it seemed to be holding. It looked like I could move forward with my ambitions for this setup, and I was eager.

And then it didn’t.

The original goal creatures for the land area, Bombina orientalis fire-bellied toads, remained unavailable for months. In the interim, I hemmed and hawed about how I would safely and economically house and dispense crickets in a home that also had two cats that get very excited around insects. A friend introduced me to black soldierfly pupae, a refrigerator-stable live food for insectivorous animals, and I was jubilant. So armed, I would be ready when the frogs at last turned up. But a deeper look into cohabitating these animals revealed a fatal flaw in my plan: their skin secretions are dangerous to other (semi)aquatic life. In a well-filtered tank with activated carbon to capture toxins, this danger could be managed, but this paludarium was anything but. By design, it relied heavily on the plants in its land area for nutrient export and thus had minimal, and eventually no, active filtration, with or without carbon. My frogs would be hazardous to everything else in the tank, in addition to requiring a specialty diet. With the existing inhabitants not easily passed to my other tank, the wisest course seemed to be to take aim at a different semiaquatic animal, and the one that seemed right was vampire crabs (Geosesarma dennerle).

A small boxy crab with bright purple legs, lighter purple claws, a dark body, and yellow eyes.
Purple with yellow eyes, you know, like a vampire.

For the majority of readers for whom this is an unfamiliar name, vampire crabs are a semiaquatic crab species from Indonesia. Their trade name comes from how the color variation initially most common in the pet trade is black with red eyes and becomes a bit strange when applied to other color combinations such as the purple-with-yellow-eyes form more commonly available at present. What I had built was ideally suited to this creature, so it became a matter of finding some…and the only place that had any I could even hypothetically access was a mail-order exotic animal vendor whose stock was inconsistently available. Live animal mail-order retail is eye-wateringly expensive, with shipping charges often double or triple the price of a single normal-sized order, so this was not a tempting prospect. My local aquarium society sometimes creates group orders to divide and reduce the impact of shipping costs, and I tried to get one started, but as a non-driver, I was the wrong person to receive the shared shipment and no one else stepped up, so the idea withered on the vine.

It was not the only thing withering. My crude egg-crate enclosure proved not quite up to the task I had assigned it. I built it to rely on the aquarium glass for support on three sides, and that technically worked, but it also meant that very little was preserving the shape of the bottom. It had none of the structural reinforcement that walls would have provided and, under the weight of its saturated soil, the unsupported edges were bowing. This lowered the soil farther into the water over time, which progressively drowned plant after plant. What did not die from insufficient light from my leftover “economy” aquarium LEDs died from having its water tolerance totally exceeded and even highly moisture-loving plants began to show signs of waterlogging. By today, a good half-dozen purchased plants had already died and others were in rough shape, even as a few of them did seem to do well in this strange, demanding environment. But I did not build this system to watch plants die, and I especially did not build it to sag in its middles and threaten to come apart under its own weight. I attempted to add additional supports and the new bend was so strong that the whole thing warped in other places instead, so, that did not help.

The water section of the tank was a bit more hopeful. For a while, my Tateurndina ocellicauda peacock gudgeons were every bit the delight I hoped they would be, establishing their pecking order and flaring their deliriously beautiful colors, every bit the match for coral-reef splendor, and I was enthralled. Then their hierarchy grew vicious and I took measures I took to stem their aggression, exchanging the most violent member of the all-male trio for a new, smaller fish, but that ultimately ended in disaster. The trio became a duo shortly thereafter, with one fish disappearing, and then only a single fish remained: the most visibly damaged of the original three. The cheeky little wonders had bamboozled me into keeping the problem fish, not the solution. That one lasted a few weeks longer and, as of about a week ago, seems to have also disappeared into the guts of my scavenging snails. My water parameter tests indicated nothing amiss, which left the cause of death a mystery. With the peacock gudgeons gone, that left a handful of small, low-energy, mostly nocturnal catfish and four species of snails as the tank’s aquatic inhabitants, far from an ideal basis for the aesthetic I had in mind.

Among those snails were recently-added rabbit snails, large conical creatures with downright goofy movement patterns whose presence I quite enjoyed, Unfortunately, the rabbit snails repeatedly wedged themselves in the space between the land area’s support struts and the aquarium glass, sometimes for days at a time before I realized they could not dislodge themselves and needed my help. I added berms of sand to all the places where this scenario could repeat, which helped keep them out of trouble, but the structure was clearly becoming a liability to everything in the tank, not just the plants within it.

A large snail with a narrow conical shell and a bright yellow body. It has large antennae.
Love these goofy little doofuses. I once watched one THBBBBBBBT in the bubbles of an airstone for 45 straight minutes after falling on its back, totally able to move but having too much fun.

In the end, it was for naught. This tank’s strange dimensions made it a perfect fit for its location in my home, but also made a properly sized hood impossible to find. I could find listings in catalogs, yes, but never in stock, anywhere, and one site has it backordered since July 2022 on my behalf with no end in sight. One last abortive effort elsewhere yielded a lid the right shape but the wrong size, useless as a solution to this problem, and I’m still hoping for a refund. No proper cover means no proper humidity control, heightened escape risk, and an elevated chance that my inquisitive cats would find movement in the land area far more exciting than they have found the tank up to this point. For an expensive prospective species in a hacked-together enclosure design that was well and truly showing its limits, that was a bridge too far. This experiment was over.

The land enclosure, made of egg crate lined with window screen. The egg crate is bent, warped, damaged, and filthy.

I sought out some additional plant pots to rescue the remaining land plants. As houseplants, they would have a better shot at not drowning. I was pleasantly surprised to find that, despite the utterly still surface of the soil, my isopods and springtails were apparently thriving within it. With any luck, they will find their new lives in plant pots as comfortable. Then, I removed the land enclosure and surveyed it one last time. It was wet, filthy, warped, cracked, and a testament to the mental effort and dubious craftsmanship that had gone into it. It also absolutely reeked of the low-oxygen mud that had become its lower layers, so, that almost certainly contributed to the challenges of this system. Then I hefted it down my garbage chute.

A 46-gallon bowfront / "euro-style" aquarium partly filled with water. It has a dark sand substrate and abundant decorative wood. The water is turbid and mostly opaque.
This will calm down by tomorrow, especially now that it’s properly filtered.

The substrate, wooden décor, and aquatic plants and animals could stay. With a higher water level and a proper filter, this tank will become something close to a West African biotope, a different long-term dream. It will not as pure as that term implies, since its Asian snails, Asian plants, and South American catfish will do better here than in my main system, but the rest of its look and future inhabitants will fit that theme. I was even able to reposition some emergent plants at the new water level and keep them in the system. What’s more, a properly fitted cover in this sort of setup is optional, albeit helpful for controlling evaporation, as long as the water level is low enough to deter jumpers. I’m thinking Phenacogrammus interruptus Congo tetras, a Gnathomeus petersii elephantnose mormyrid, and my all-time favorite fish, so loved that it is inked on my body, Pantodon bucholzi, the African butterflyfish, one more time.

A black fish with a narrow caudal peduncle, a back-swept dorsal and anal fin, and a long lower lip.
I really want to try this animal. They sense their world with electricity!

It is the end of an era, and the start of something new and, hopefully, beautiful.

Paludarium 2: Tragedy Boogaloo