Within the limits of a 5-gallon aquarium, forming a breathtaking aquatic landscape is not only an art but also a test of skills. For those of us who have been captivated by this hobby for years—myself included—there’s no denying the appeal of an aquarium this size. On the one hand, it offers similar opportunities for arrangement and beauty that any tank would; on the other, it presents an added challenge in that there’s a finite space to fill, and filling it requires a certain inventiveness. Love it as I do, that 5-gallon tank would seem to be the very definition of a “small” canvas on which to work.
When I began to focus on nano aquariums, I was a little intimidated. It’s easy to think that since the aquarium is small, it should be simple, but the opposite is true. For everything you do, whether it’s picking plants, choosing fish, or deciding substrate, you have to account for the instant, small-scale effect it will have on the chemistry of this body of water. I had a bust moment when my first 5-gallon tank crashed so dramatically that I thought about giving up. I had stocked it to the gills with fish, of course; what else would you do with an aquarium?
Changes in chemistry happen fast when the body of water is small and the number of living creatures within it is proportionately high.
A 5-gallon aquascape setup is simple, but deceptively so. To create a masterpiece in such a confined space requires no small amount of artistic vision and practical know-how, both of which I think I can provide a suitable amount of as I have tried my hand at a few of these 5-gallon aquascapes myself. Actually, I think I might have created a few disasters along the way, with those confined spaces leading to a couple of overly ambitious and, in hindsight, very impractical attempts at designs.
When I plan a 5-gallon aquascape, I start with the vision. What is the overall theme? This is not something to pick on a whim; it informs every choice down to the smallest detail. I had a theme of “mountain” work for me once. I used Seiryu stones, which look great and come in sizes that can be used to create features. This is not a paid endorsement; I’ve learned from experience that when it comes to this kind of hardscape, the rock has to be right or else the whole thing flops. And what is “flop”? When your tank is so tiny that whatever is in it can’t help but look cramped, and when your vision is all but indistinguishable from what the same setup would look like “sans aquascaping.”
The foundation of any aquascape—of any underwater landscape, for that matter—is its hardscape. This is even more true for a 5-gallon tank, where space is at an absolute premium. Hardscape is your skeletal structure, the part of the aquascape that is not alive. The materials you use in this part of the tank must be chosen carefully for scale and for visual impact because they simply can’t be dominant. This is a ridiculous thing to say, but I will say it anyway: always think of your materials when they are placed within the context of the hardscape. I made plenty of dumb mistakes picking out materials when I did not think of them in this way.
For a 5-gallon aquascape, Dragon Stone (Ohko Stone) or Seiryu Stone makes an excellent choice. With either of these natural-looking stones, you really can’t go wrong. They have textures and colors that work well as focal points and really pop when viewed underwater. My preference, when using either of these stones, is to go with a trio of stones of varying sizes, shapes, and colors that creates balance. That can work sustainably within any aquarium thanks to the compact and hardy nature of both Dragon Stone and Seiryu Stone.
This is the area where I get most excited—plants—because they are what create the look of depth and complexity in smaller aquariums. This was, at least, my working theory before I strove toward plants that were supposedly the right size and growth rate but have since proven to be something close to the opposite in two of my more aquascaped disasters. The first involved planting grass that should have been in larger, shallower spaces on the scales. The second involved using a species of large foreground plant in a tank that is a little less than half a foot deep—that species has since been eliminated, and balance has returned to the nano, codename “Sea Slug.”
I prefer to stick with dwarf species and carpet plants that keep a low profile but still bring texture and interest to my hardscape. My go-to plants for a 5-gallon tank include Hemianthus callitrichoides (Dwarf Baby Tears): This is a classic carpeting plant that creates a lush, green foreground. It requires high light and CO2, but the payoff is immense—nothing compares to the look of a dense, verdant carpet in such a small tank. Cryptocoryne Parva: If you’re after a low-maintenance plant that stays small, Crypt Parva is a wonderful choice. It grows slowly, which makes it perfect for a 5-gallon tank, and it can tolerate a range of light conditions as well.
Anubias Nana Petite: This is one of my personal favorites. I use it in nearly all of my small tanks. Its tiny leaves and hardy nature make it ideal for adding detail to rocks or driftwood.
A small piece of driftwood and quantities of Anubias Nana Petite were the sole ingredients in a recent aquascape I attempted. I wanted it to be minimalist, bonsai-like, and breathtakingly simple. It is all those things and, regrettably, yet to be a calming force in my recently retooled living room since it has yet to be inhabited by fish.
Proper illumination is critical in small aquariums. When it comes to lighting these compact tanks, achieving the right balance can feel like a performance—one that my 5-gallon has certainly judged me harshly for in the past. If you give your plants too much light, you’re begging for algae. If you give them too little, they will suffer. In my experience, the best way to avoid a disaster either way is to use a light like the one by Chihiros that has plenty of adjustability built into it. Their LED systems are deceptively powerful, and mine has been a complete non-issue in terms of routine maintenance, which is a big-plus because a small tank is already a routine-maintenance kind of grind.
There are other crucial aspects in a small aquarium where you don’t want to skimp. Easy to maintain, sponge filters create a gentle current and allow for a slow-speed environment—perfect for a nano-scale tank. This is because sponge filters allow the slow, gentle “push” of water, which is just enough to keep things in suspension and moving to the right places while not disturbing light-sensitive mosses and shade plants that are more at home in low-speed environments. The trick, then, is to find a filter that fits within the confines of the aquarium without disturbing the aesthetic. And yes, there are a lot of different possibilities out there: foam, canvas, and PVC pipe, to name a few.
If you are truly intent on forming a flourishing aquascape in a 5-gallon setup, I strongly recommend that you invest in a small CO2 system. From what I’ve seen and experienced, this is the path to the best growth and health for your plants. I consider it somewhat necessary for a “high-tech” aquascape. Inasmuch as I have loved my low-light, low-tech work, with the addition of CO2, you get increased growth rates as well as a maintenance of that deep green color, even more so with wayward dwarf baby tears (Hemianthus callitrichoides) and other light-hungry species. The systems that are made for nano tanks are perfect for a true 5-gallon aquascape like this one.
One of the realities of working with a 5-gallon aquascape is that it requires regular and reliable upkeep. This is something I’ve come to appreciate, even though I know many aquarists, particularly those just starting, tend to be put off by the idea of having to do so much “hands-on” work. But trust me: if you want your nano tank to be a thriving part of your home and not just an elaborate container for plants that slowly decays over time, you will need to maintain it on something very close to a full-time basis.
One time, I let a 5-gallon aquarium landscape sit for a couple of weeks while I was away and, upon returning, found algae rampant in the tank. The tank had tipped cleanly out of balance and into the foul-smelling territory of decay. It took weeks to get the tank back to any semblance of the pretrip condition. Now, as I said before, I don’t believe that kind of intensive maintenance is necessary for a tank that houses any kind of life, but that was a serious case of neglect, and I paid the price—not only with money but with my time and emotions in the visible aftermath of neglect.
When it comes to small aquariums, pruning plants is a delicate art. This is a knowledge base I’ve built over the years, and it has served me well in creating rather convincing natural underwater scenes. In a 5-gallon tank, just about anything can get too dense before you even notice, and when that happens, poor water movement and plant decay can set in. I try to activate a seeming scene just enough to maintain a “natural” look and “fill” without going to excess. This seems a fine line to walk, but it keeps me somewhat alert, and I like to think it also keeps my obsessing to a minimum.
A frequent inquiry concerns the right way to stock a 5-gallon aquarium. Time and again, I learn that the less-is-more principle holds true. It’s all too easy to be lured into including many different types of small fish. But in this miniature space, adding too many organisms—especially ones with larger territorial needs—can quickly lead to both poor water conditions and poor quality of life for the real residents. On the other hand, if you keep the bioload low (something else that’s too easy to overlook when we’re being seduced), choosing just a couple of species of small fish and/or invertebrates can not only serve the aquarium well but give it some pleasing visual interest.
If you really want to include fish, I would suggest you choose microscopic types, such as the Chili Rasbora or the Endler’s Livebearer. These two fish stay small and are very active, which adds “life” to your aquascape. And while the two livebearers I mention here (both of which I’ve kept successfully) have a good amount of color for a densely planted 5-gallon, don’t discount the contrast you could get with something like green Guppies.
Even with the difficulties inherent in working with a 5-gallon tank, I can claim with certainty that they offer some of the most rewarding challenges in aquascaping. There’s something beautiful about the art of crafting a small-scale, vibrantly living ecosystem. It requires one to pay attention to every single detail, from load selection (plants, fish, invertebrates, etc.) to the chemistry of the “stuff” in the tank. But in the end, these “paludariums” (part-aquarium, part-terrarium) may be small, but they pack a huge punch in part of the living room that is their home.
If you are considering a 5-gallon aquascape project, I urge you to take it on as a rewarding challenge. Allow yourself plenty of time for planning. Make deliberate choices for your plants and hardscape. Go ahead and try out a few different things; this is an excellent avenue for experimental art. You may well end up creating a little beauty that will make you stop and stare.
