All-in-one aquariums under 50 gallons are very popular because they are affordable and easy to set up. Brands like JBJ, Innovative Marine, Oceanic, Red Sea, and Fiji Cube have all developed their own AIO-style aquariums. These tanks can support fish and coral without the need for much additional equipment, which makes them very appealing to first-time reef tank owners. AIO-style aquariums are so popular now that many ingenious members of the aquarium community have come up with a variety of creative ways to modify the tanks to make them even better and more functional. Here is a list of some of our favorite upgrades that you can easily accomplish on your very own AIO-style aquarium. 

Lighting Upgrades

Removing the plastic hood that houses the stock lighting will make the biggest impact on your all-in-one tank. This is such an impactful change because it will allow you to not only upgrade your lighting, but you'll also gain access to the filtration compartments so you can add upgrades that might not otherwise fit.

There are a number of great LED lights that will work on these types of aquariums once the hood is removed. The Kessil A160WE, Red Sea ReefLED 50, EcoTech Marine Radion XR15w Pro, and Aqua Illumination Prime are among our favorites. Just be sure to get the appropriate mounting hardware for attachment to your tank or suspension kit for hanging from your ceiling or light rack.

If you prefer to keep the hood on your aquarium, you can still upgrade the stock lighting with some LED Strip lights.  Reef Brite's XHO and LumiLite Pro strips will work out great and are most certainly an upgrade from the stock lighting on most tanks in terms of both color and output. In this case, every tank is different but it will entail removing the existing lighting electronics and then mounting the LED strips up inside the hood.  Really, it's just a matter of attaching the strips and ensuring they fit.  All of the wiring will already be done.

Nano Protein Skimmers
  1. PSK-100H Hang-On-Back Protein Skimmer
    PSK-100H Hang-On-Back Protein Skimmer

  2. BioSkim DC Protein Skimmer
    Innovative Marine
    BioSkim DC Protein Skimmer

  3. Midsize NuvoSkim DC Protein Skimmer
    Innovative Marine
    Midsize NuvoSkim DC Protein Skimmer

  4. QQ3 Hang-On External Nano Skimmer
    Bubble Magus
    QQ3 Hang-On External Nano Skimmer


Adding A Protein Skimmer

A skimmer is hands-down one of the best filtration upgrades for a small tank.  The challenge here is finding something that is small enough, yet actually works and is worth your efforts.  Small "nano" skimmers can be finicky which is simply because the limited size makes it difficult to achieve a steady skim action. While most small skimmers do work to create foam and collect some waste, a constant foam head that is pulling organic waste 24/7 can be difficult to achieve. Good news, there are a handful of these little skimmers that work far better than others.  

Adding a protein skimmer is also much easier once the hood is removed because you'll have so much more room available to hang a skimmer off the back or submerse something into the filtration chambers directly.  The AquaMaxx HOB-1.5 or Reef Octopus Classic 100 are the most effective hang-on options. AquaMaxx's Bullet-1 is also a great choice for tanks under 20 gallons. While these are bulky, they will give you the best performance. 

If you prefer to keep things a bit more streamlined, there are internal skimmers that will submerse directly into your filtration chambers.  This is going to be very specific to your tank in terms of which ones fit.  Those chambers are small and the exact dimensions are going to limit your options. The first step is to physically measure the internal dimensions of the desired chambers, length x width x height.  The Tunze Comline DOC, EShopps Nano, and AquaMaxx NF-1 are the best options and will perform pretty similarly. Just be sure and double-check those advertised skimmer dimensions to ensure they will fit into your particular tank.

Boost Filtration With Media Reactors

A media reactor is a great way to improve the water quality in your tank with carbon and/or GFO media. The Two Little Fishies Phosban 150 is a great choice because it includes a hang-on bracket that easily attaches to the back of your tank. The entire line of AquaMaxx FR reactors and Innovative Marine MiniMax reactors are also great choices for mounting inside the filtration compartments and helping to reduce clutter. 

Refugiums Are Rad!

One of the more creative modifications we have seen is turning one of the back chambers into a natural refugium. Peeling the back cover off the tank and using a magnetic refugium light like the JBJ Nano-Glo or Innovative Marine ChaetoMax is super easy and surprisingly effective for nutrient control. Just be sure to keep the area clean and harvest the algae as needed.

Add An ATO - Auto Top Off System

An auto top-off system is a necessary piece of equipment for small tanks because evaporation causes salinity levels to drop much quicker compared to larger tanks. An ATO also saves you time because they eliminate the need for daily top-off, plus you get a consistent water level which will keep your protein skimmer, if you have one, performing optimally.

When mounting the ATO sensor or float switch on an AIO tank, you will need to place it in the chamber that actually changes water level with evaporation—which is the pump chamber.

The final chamber before the water is pumped back into your aquarium will be the only chamber where water level fluctuates on a daily basis. The tanks are designed to operate like this and are made possible by the internal baffles that divide up those filtration chambers and direct water flow accordingly. 

Check out the Tunze Nano or Reef Breeders Prism - our best-selling ATO systems for smaller tanks.

Flow Is King - Use A Powerhead

Because small, all-in-one tanks have become so popular in the past 10-15 years, many of the leading pump manufacturers now offer nano-sized powerheads specifically designed to produce wave motion and sporadic flow in these tiny environments. 

We generally will recommend 10-30 times your total tank volume per hour, per pump. This calculation comes in handy when choosing the right powerheads.  For example, a 30-gallon tank should have powerheads that will move somewhere between 300 - 900 GPH each. While one pump will often suffice in a small tank, using two pumps is not uncommon just because water flow is so critical for the health of a reef tank. Using a controllable pump comes in really handy with smaller tanks because you can simply adjust the output to accommodate your particular tank's needs. 

Here are some of our favorites: