Thinking about adding an aquarium sump tank to your display?
This article will help you better understand what an aquarium sump is, why you may want one, and where to buy online and provide product reviews of the best setups.
Table of contents
What is an aquarium sump?
An aquarium sump is a vital piece of equipment–a tank, really–that sits underneath your display tank where you keep your filter, heater, protein skimmer, and other equipment. If you buy a commercially made kit, it looks something like this:
Why keep all of your equipment in your aquarium sump?
- For starters, when kept in or on your display, thank you, your equipment can be an eyesore–keeping it below the tank and under your stand keeps it out of the way and out of sight.
- Keeping the equipment in the aquarium sump area also allows you to have easy access to it without disturbing the living creatures in your aquarium when you perform maintenance or if you have to replace it.
- An aquarium sump also allows you to expand the water volume of your system, essentially providing your tank with more stability and the capacity to support more saltwater fish, corals, and other invertebrates without the need for the larger footprint of a larger tank.
For example, my current display tank is a 92-gallon corner aquarium, and my sump holds about 16 gallons of water, so my total system volume is around 108 gallons of water.
In my case, the increase from 92 to 108 is meaningful, but now consider the relative difference of expanding from 55-gallons to 71 gallons. That’s a pretty big deal.
Aquarium sump design
The basic design of an aquarium sump is as follows:
- Water flows from the display tank above down into the aquarium sump
- The water generally enters the sump area and flows through a filter sock, which removes any large particles or debris
- The water then enters the chamber holding the protein skimmer, where the water is then skimmed using foam fractionation to remove organics
- Space permitting, the water then enters the refugium area, where the water is purified biologically
- Water then passes through baffles to trap microbubbles before
- Return pump pushes the water up and back into the display tank area
Here is a more detailed breakdown of each of the steps listed above.
Typically, a filter sock is used as a first filtration step to catch and remove any particles.
- Water flows into the filter sock from the display tank
- Suspended particles in the water get trapped in the sock and removed from the water
- Socks will get dirty and clog up–when they do, they need to be replaced
Filter sock is your sump tank filter
If you have experience keeping freshwater aquariums, you may be wondering what type of filter you put in your sump tank.
You might be surprised to find out that, for the most part, the aquarium sump filter is something called a filter sock.
A filter sock uses a fabric or mesh material roughly in the same shape as a tube sock.
This filter sock covers the pipe of water drains into the sump from the display tank and removes any large particulates before allowing the water to flow through the rest of the aquarium sump.
Check out these filter socks online.
Most times, reef aquarium hobbyists will also install a protein skimmer in the aquarium sump, as well. While not typically called a filter, per se, a protein skimmer does provide a water purification step.
Another common way to purify water in an aquarium sump without a specific aquarium sump filter design is with something called a sump refugium, which I will cover soon, as well.
A protein skimmer is a device that cleans your reef aquarium water using nothing but physics and bubbles–or is it bubbles and physics?
I’m not sure what the order is–but the point is that these tiny scrubbing bubbles remove all kinds of nasty stuff from your aquarium.
You could technically install the protein skimmer anywhere you wanted, within your sump. Still, I prefer to put the protein skimmer upstream of the refugium because putting the protein skimmer after the sump refugium would suck up any of the beneficial invertebrates your refugium may be producing and skimming them out.
For more information about protein skimmers, check out this article here.
The aquarium sump refugium is a naturalized part of the sump setup, where impurities are removed from the water naturally by the organisms living in the sump refugium area.
Many aquarium owners will use the aquarium sump refugium area to keep a deep sand bed.
A deep sand bed is live sand that serves as home to both aerobic and anaerobic bacteria. These bacteria act as a waste-processing plant inside your aquarium sump and turn ammonia into nitrites, nitrites into nitrates, and completely remove the nitrates from the system.
In addition to a deep sand bed, a typical sump refugium will also have a macroalga, like cheatomorpha, and sometimes has other tiny invertebrates.
It is also popular and common to add live rock to the aquarium sump refugium area to provide additional biological filtration capacity and a substrate for your invertebrates and bacteria to grow.
Because the sump setup area is below your display tank and away from the predators you keep in your tank, tiny beneficial invertebrates called copepods often live and reproduce, forming a beneficial and natural live food for your fishes and corals.
Then, the water generally flows through a series of baffles.
How baffles work
Baffles are narrow walls that force the flow of water over and under the walls, sequentially, to trap bubbles.
- Bubbles are forced (sometimes) under the first baffle due to water flow if the water flows quickly.
- The bubbles then get trapped at the top of the second baffle, unable to go back under the water–remember–bubbles want to float up.
- Bubble-free water flows under the last baffle.
Not all sumps will have this many baffles, but this is intended to be a generalized concept depending on water flow.
A return pump then sends the water up against the force of gravity and back into the aquarium. You can learn more about return pump options here.
DIY Aquarium Sump
Since the commercially available aquarium sump options tend to be slightly on the pricey side, many people chose to build their own DIY Aquarium Sump. This can be as simple as a 10 or 20-gallon aquarium where the water collects and is recirculated, or as sophisticated as some of the more popular commercial models, with filter socks, baffles, an aquarium sump refugium, and even ATO devices.
The advantages of building a DIY Sump are cost savings and the ultimate ability to customize. The downside is that you have to design it and do all the work yourself–which is not always a disadvantage.
Building your own DIY aquarium sump is a project on its own–but here is a helpful video to check out in the meantime:
Where to find an aquarium sump for sale, and what are the best models?
You can generally find these for sale at a local pet store that specializes in saltwater aquarium fish. You can also find a lot of great options online.
Here are is a product review for a few of the most popular design models available on Amazon.com:
ProClear Aquatic Reef Sump RS100
The ProClear Aquatic Ultra Reef Sump RS100 is rated for tanks 100 gallons or less.
Made in America, the dimensions are 24″ x 10″ x 16″, and they use a standard 200-micron bag/filter sock, which makes them easy and inexpensive to maintain over the long haul. This design uses a bubble diffuser tube to remove bubbles and lower noise.
Aqueon 34500 ProFlex Sump
Another good option is the Aqueon 34500 ProFlex Sump. This sump is designed to be flexible enough to allow you to create the sump design of your choice. Do you want an old-school wet/dry filter?
Hopefully not for a reef tank, but maybe you want to be able to use this with a FOWLR or Freshwater tank after you’re done–no problem.
Want to have an aquarium sump refugium? No problem. Need to adjust the water height for your protein skimmer? No problem.
The Aqueon ProFlex Models are available in a few different sizes:
Model 1: Rated for aquariums up to 55 gallons – 19 7/8 ” x 9 7/8″ x 17 1/4″
Model 2: Rated for 75 gallons- 29 7/8″ x 9 /8″ x 18 7/8″
Model 3: Rated for 110 gallons- 25 7/8″ x 13 3/4″ x 17″
Model 4: Rated for 210 gallons- 36″ x 13 3/4″ x 18 7/8″
Some things to watch out for– several people who purchased this unit online reported the sump arriving with a crack in it, or broken parts, etc.
Check out those reviews here.
You should inspect anything you purchase online, but since you will be plunking down a couple hundred dollars for a sump tank, you will want to carefully inspect these when you receive them to make sure they are defect-free.
Nothing worse than coming home one day to a soggy carpet because your sump leaked.
Another con here is that owners report that the filter socks are challenging to remove. Not good.
Eshopps AEO14005 Reef Sumps
The Eshopps 14005 RS-100 is designed for simplicity and affordability. Rated for a 75-100 gallon aquarium, it is a great option if space is limited in the stand under your display tank.
The dimensions of the Eshopps 14005 RS-100, according to the manufacturer’s website, are 24″ x 12″ x 16″. The skimmer compartment is 9″ x 11.5″, and it is fitted with a 7″ micron bag/filter sock.
It comes with a flexible hose that you can attach to your bulkhead or overflow and a pre-filter sponge that rests between the baffles to help provide biological filtration and dampen noise.
The best reasons to buy this model?
It is quiet, compact, and affordable. Something else to consider is the aesthetics. Do you like the elegant, clean look/design?
A reason not to buy it and get a different model?
If you have space for a larger sump setup, you can select a larger model that will allow for sump tank refugium. You also need to buy the proprietary filter sock. It will be challenging to go generic.
If you have a tank larger than 100 gallons, and/or if you have more space under your aquarium to fit either a 30-inch long or 36-inch long sump, consider getting the Eshopps 14010 RS-200 or Eshopps 14015 RS-300 models.
How quiet is the Eshopps Reef Sump?
One thing I love about the Eshopps reef sump is how quiet it really is. But Don’t take my word for it. Watch this video with the volume turned up:
The Eshopps 14005 RS-100 reef sump is rated for a reef aquarium 100 gallons or less, dimensions: 24″ x 12″ x 16″
Eshopps 14010 RS-200 reef sump is rated for a 125-225 gallon aquarium, dimensions 30″ x 12″ x 16″
Eshopps 14015 RS-300 reef sump is rated for a 225-300 gallon aquarium, dimensions 36″ x 14″ x 16″
Best Aquarium Sump Review: What is my recommendation for the best sump setup?
Looking for the best aquarium sump for your reef tank?
Here is my review and recommendation.
Proclear is an option–but there aren’t many reviews–that makes me a bit nervous.
I am initially attracted by the flexibility of the Aqueon ProFlex design. I like the idea that there are standard accessories and ways to change things up, but there are two minimum requirements (for me) when looking at a sump setup–and that is:
- It can’t leak
- Has to be easy to maintain
- Difficulty getting the filter socks out and the fact that many of these are reported to have arrived cracked leads me to skip that one.
For me, the best blend of attractiveness, the simplicity of design, and functionality are the Eshopps Reef Sumps.
You will want to pick the largest model that will fit under your aquarium.
What to read next
Hopefully, you found this article all about aquarium sumps helpful. If you are looking to set up your reef tank with the best equipment and gear, you will enjoy reading these other great articles:
What do you think? Would you like to add anything? Please leave a comment below if you do.