A short while ago, I started a journey to find the best rimless aquarium. I already have one aquarium running, but I wanted to experience starting over and the freedom of starting another aquarium from scratch. It needed to be small, but I was hoping for something bigger than most reef jars. I haven’t been on the market for a new saltwater aquarium in years, and I was surprised at all the options that are available. Compared to even just a few years ago, there are so many options.
When I started this journey, I thought I was going to end up with a JBJ Nano Cube or a Coralife model. Something that looks like this:
JBJ Nano Cube
By the way, tons of those systems have been purchased. They are great products and are exactly what I thought I was going to purchase, but I wanted to find the perfect tank for what I was looking for. As I searched around for a nano aquarium, a slightly different design caught my eye. The design is called the rimless aquarium.
What is a rimless aquarium?
It is a fairly straightforward conclusion to make that a rimless tank is an aquarium…without rims…but why is this even a feature worth mentioning? If you take a look at the standard glass aquarium, the design is relatively simple. The side panes of glass are connected to the bottom pane of glass with aquarium-safe silicone.
Simple enough. The engineering problem with that design is that once you fill the aquarium with water, the water (inside the aquarium now), exerts a force on the glass, essentially pushing it out.
In those older-style tank designs, the frame provides the structural integrity that keeps the glass in place, which keeps the water inside the glass, which allows you to have the amazing aquarium in your home without causing a big flood.
So the rim has traditionally been one of the dominant eyesores associated with a traditional aquarium, as far back as I can remember. At first, much like Henry Ford’s Model T, you could have an aquarium in any color you wanted, as long as it had a black rim.
At some point in time (I’m really dating myself here, sorry), I bought a glass aquarium from Oceanic that had “oak” rim. But even with my current aquarium, the rim is the most prominent feature of the whole darn tank.
So, when I started to see how cool the rimless aquariums looked, I realized that was the design for me and the look I was going for.
If you’re trying to decide for yourself, a rimless aquarium isn’t any better or worse than an aquarium with a rim. It is simply an aesthetic, design and style element that will either suit your taste or not.
Because I’ve grown so used to the traditional aquarium designs, I found the sale, modern designs of the newer rimless aquariums to be exactly what I wanted for my office.
There are a lot of options to choose from–so let’s break down some of the similarities and differences across models.
Specifications and features
Here are a few of the basic specifications and features that are available with the models available today:
The designs I found ranged in volume from about 2.6 gallons (Fluval III Model) to 10 gallons, about 10 liters to 38 liters in volume. The most common size (and the size I was personally most interested in) was 5-gallons. It’s the perfect size for a small tank.
There appears to be essentially two shapes/design schemes for a rimless aquarium. They are almost always rectangular in shape. Some models are taller than they are wide, and others are wider than they are tall. All the options either have a crystal clear glass or acrylic walls.
For the models compared here, the prices generally ranged from about $45 on the low-end and $150 on the high-end. $150 isn’t the end of the world, especially if this is going to be your main attraction–but for me–I was looking for a tank to be a nice, modest addition to a small room.
Most of the all-in-one models have a compartment where 3-step filtration (mechanical, chemical, biological) occurs. One of the models shown below uses an in-tank filtration unit. Functionally speaking, a filter is a filter, however aesthetically, the in-tank filter means you’re literally looking at the filter inside the tank.
All of the main options I found have energy-efficient LED lights. This is good because these aquarium lights are the least expensive to run, they don’t give off a lot of heat, which could be a bad thing with a tank this small, and they tend to last for years.
Product Review and Comparison
There are several different rimless aquarium suppliers. It can be a challenge to determine which model to do with. Here is a quick overview of some of the most popular options and some considerations to consider.
Penn Plax has an attractive Curved Corner Glass Aquarium. It’s a 10-gallon tank and is much more attractive looking than the traditional rectangular 10-gallon tank I grew up with. As the name implies, there are curved edges and it is rimless, which creates a cool, sleek look. The glass panes are held together in the back corner with a very small bracket.
This kit comes with a small LED light fixture and an in-tank (internal) filter.
While this tank is a good price and looks very nice, it still needs a heater (as do most of the tanks of this size), a powerhead water pump and would likely need a lighting upgrade if used for coral. Compared with other available models, the ‘in-tank filter’ (you can see it in the top left in the picture above) is a bit of an eyesore.
I also wonder if the curved glass in the front of the tank is going to create an additional maintenance burden to keep that part of the glass clean and free from algae. A standard mag float device would have a tough time getting in there, I bet.
The tank has a clean profile and design. Check out the price here.
For my taste, this was not the perfect option, so I kept on shopping.
Perhaps one of the most intriguing rimless aquarium options, for a guy like me who likes added features (I am distracted by cupholders and other options designed to tip the decision in favor of buying one product over another), is the EcoQube C (get it, it spells Eco Quebec…), which seems to combine two very popular trends right now—it is part rimless aquarium and part aquaponics. The image shows a cute little nano aquarium with what looks like a basil plant growing out of the top of it.
While aquaponics isn’t very practical for the saltwater aquarium hobbyist, my monkey-brain immediately went to work and decided it could be used as a mangrove-nano-system.
Upon closer inspection, the tank seems to be more of a high-end betta bowl than a pico aquarium (which is a very small version of a nano tank). There is no filter, much like a betta bowl. The plant is the filter.
Interested in learning more about this model?
This was not the tank for me, for right now, but perhaps something for the future, for the kids, to keep in the kitchen.
Fluval Spec III
Another interesting option is the Fluval Spec III. I think the name is tied to the size of this rimless aquarium…it’s 2.6 gallons…so I think the marketers there are perhaps rounding up. Anyhoo, this pico aquarium does have some interesting features.
This tank is not quite a cube, but it is close. It has a hidden 3-stage filtration system in the back of the tank and a 31 LED light. If you are seriously space constrained, this is a good option, but it’s a bit too small for me–and isn’t exactly the look I’m going for. It does come at a pretty good price.
Marineland Portrait Aquarium
Marineland sells a rimless aquarium they dub the Portrait Aquarium. While rectangular in shape, this tank is taller than it is long (think portrait printing vs. landscape printing with your computer printer).
The 3-step filter is hidden behind a back panel. There are blue and white LED lights (which enables you to create a dawn/dusk or moonlight effect, if you wish). The tank also is cleverly designed so that it looks like it is floating on a stand, rather than sitting directly on your desk.
I really like the light—it is hinged, so rather than lift it out-of-the-way when performing water changes, etc., you can just push it back on its hinge. Cool.
The size was 5 gallons, perfect for what I was looking for. There is a glass canopy that entirely closes the top of the tank. It also slides to the back, to give you easy access to the tank to make feedings easier.
It’s clear that Mainland built this tank for aesthetics and functionality. If you’re in the market for a glass aquarium, this is a solid choice, in my opinion. While I’m writing this, I checked, and there are over 300 reviews with an average rating of 4.5 stars.
This is also one of the most affordable rimless aquarium options on the market.
One big question I had with this tank, and with all the rimless aquarium options, was whether or not the LED lights would be powerful enough to sustain some easy-to-keep corals. While aesthetically pleasing, the portrait orientation of the tank actually exaggerates that concern.
The deeper the tank, the stronger the light needs to be to reach the bottom of the tank and provide enough light (the measurement is called PAR) to sustain photosynthetic (coral) growth.
The Marineland Portrait looks to be a cool option, but not exactly what I was looking for.
Another interesting option was the Fluval Edge. From an aesthetics perspective, this is the tank that caught my eye the most.
The beauty is clearly the focal point of a room. The filter is hidden away, and it comes with a bright 21 light LED. While the open-top design is part of the unique charm of the Fluval Edge, from an aesthetics perspective, the fact that it doesn’t have a lid did concern me, because I have had my fair share of carpet-surfing fish, over the years.
For me, a tight-fitting lid is a requirement. So while I loved the look of this tank. It wasn’t the perfect tank for me.
Fluval Spec V
Last and certainly not least, is the Fluval Spec V. This is also a 5-gallon acrylic tank with a hidden filtration area. There are Fluval replacement packs for activated carbon.
Unlike the MARINELAND PORTRAIT option, the FLUVAL SPEC V is longer than it is tall and comes with a 37 LED lighting system. For what it’s worth, I prefer this layout, because it maximizes the footprint, which creates ‘usable environment’ in my nano.
By definition, space is limited in a nano aquarium, and my perception is that the smaller but more spread out design creates more ‘territory’ for my future fish inhabitants. It also distributes the weight a little more, which is an extra insurance in support of the tank not causing any issues (from weight) on my desk/bookshelf. A 5-gallon tank will likely weigh more than 40 pounds once filled.
There is a lid, that fits nicely on the top of the rimless aquarium, with an opening in the middle (that reminds me of the Dallas Cowboys Sports stadium enough it almost talked me out of it). What I like about that feature is that it enables gas exchange and maximizes the light that gets to the bottom of the tank, suggesting it would be a good option for some hardy soft or mushroom corals.
At the time of this post, there are well over 300 customer reviews for this product on Amazon and an average rating of 4 stars.
The Fluval Spec V benchmarks very closely with the Mainland Portrait. You won’t go wrong with either option. I personally broke the tie and went with the Fluval model because I preferred that model’s shape and look, LED light and the lid that prevents fish from jumping out, while simultaneously maximizes the airflow (for gas exchange) and light penetration into the water.
The biggest con about this tank, to me, is that you have to lift up and move the light (I turn it backward) when you need to open it up or take off the lid. I minor hassle, but a hassle, compared with other models on this page.
The two things I added to my Fluval setup were: a small heater and digital thermometer. I went with the Tetra HT 10 model heater because it was the smallest I could find. It doesn’t fit ‘well’ in the filter area, but it does fit, ‘jammed in there’. Which is nice, because now it is out of the way and not visible in the tank.
Conclusion: which model did I pick?
While I would have been and could have been happy with a few of the models reviewed on this page. I personally put my money (okay, not exactly my money, but I requested it as a gift) on the Fluval Spec V acrylic tank.
I’m sure it’s not for everyone, but I wanted to share my logic with you in hopes that it helps.
Update: I’ve been quite happy with my purchase. This is a sleek looking tank that is the perfect size for my office. The only thing that wasn’t as good as I had hoped was my conclusion about the Fluval lid keeping fish from jumping out was WRONG. I actually lost one of my clownfish. Somehow they jumped out anyway–insert sad face here. Otherwise, I’ve been a happy camper.
If the Fluval V seems like the rimless aquarium you would like