4 Reasons Not to Knock Nano Aquariums

Nano aquariums boast lower initial and ongoing costs compared to larger systems

Nano aquariums boast lower initial and ongoing costs compared to larger systems

One of our earliest posts here at Saltwater Smarts was titled “4 Reasons to Start with a Bigger Saltwater Tank.” In it, we outlined the various benefits of starting with a larger aquarium and the potential drawbacks to downsized systems—instability of water parameters, fewer stocking options, etc.

We still think it’s best for beginners to get their feet wet with a larger tank, but as several of you nano-keeping salties out there have pointed out, the pro/con balance doesn’t tip entirely in favor of bigger systems. Nanos have their plusses too. Here, in no particular order, are four of them:

#1 Significant cost savings

Both initial and ongoing expenses are considerably lower for nano aquariums than for their larger counterparts. Not only are equipment costs more manageable, but also:

  • You don’t need much in the way of live rock and substrate material for biological filtration and aquascaping.
  • Fewer pumps are needed to create adequate circulation in the system.
  • A single, small light fixture will suffice for illumination—and, therefore, there are fewer bulbs/tubes to replace.
  • You get more mileage from your synthetic sea salt supply because you don’t need to mix as much salt water.
  • Smaller electronic components draw less power, saving on utility costs.

#2 Space isn’t an issue

Large aquariums take up a commensurately large amount of space in the home. Thus for apartment, condo, or dorm dwellers—or the otherwise space-impaired—a large tank just might not be in the cards. Nanos, on the other hand, can fit in virtually any living or office space.

#3 Weight isn’t much of an issue

When I set up a 125-gallon FOWLR tank in the living room of our then 85-year-old home, you can bet I was sweating the stress all that weight would exert on those old floors. I could just imagine running into the living room after hearing a loud crash and looking down at a very wet basement through an aquarium-shaped hole in the floor. This really isn’t a concern with nano tanks. Smaller tanks = smaller catastrophes.

Also, if the initial location of your nano aquarium isn’t working out for some reason, no worries! Owing to their very manageable size and weight, moving nano tanks is a snap compared to larger systems.

#4 Water changes are oh so easy!

We’re always beating the drum for regular partial water changes here at Saltwater Smarts. This chore is so much less onerous when you’re dealing with a smaller system. Consider that a 20% water change in, say, a 20-gallon tank involves siphoning out and replacing only 4 gallons. By contrast, if I want to change the same percentage of water in the aforementioned FOWLR system, I have to remove and replace 25 gallons.

Are there other benefits?
So what have we overlooked? If any of you proud nano-keepers out there have some points to add to this list, please share them with your fellow salties in the comment section below.


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About Jeff Kurtz

Jeff Kurtz is the Co-founder/Editor of Saltwater Smarts, former Senior Consulting Editor for Tropical Fish Hobbyist Magazine, and the aquarist formerly known as “The Salt Creep.” He has been an aquarium hobbyist for over 30 years and is an avid scuba diver.


  1. I kept a 2.5g tank for a while and indeed the best part about it was the relative ease of maintenance. I could do a water change in like five minutes (excluding mixing the water of course) and if there were any problems like troublesome algae or whatever I could pull the entirety of the rockwork out with ease.

    • Jeff Kurtz says

      The ease of algae control in a nano is a great point, Kevin! It’s sort of like managing weeds in a planter versus a larger garden or landscape.

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