How to build a No maintenance saltwater aquarium


Most people who enter this hobby start out with all the ambition in the world.  They get the tank up, running and stable, then, unfortunately, over time as the newness wears off, the drudge of routine maintenance becomes problematic.   In many cases, the tank gets taken down within a year or so.  The answer to counter this and achieve longevity and fulfillment in the hobby is to plan properly and build a No-maintenance system (actually a very low maintenance system for long periods of time) with the most practical automation possible.   In this article, I’ll explain how to do this, and reveal one crucial element to be successful.

Note of caution

This is not an in-depth how-to article on every aspect of how to start up and care for a saltwater aquarium.  Rather, it’s an overview of a very low maintenance, robust system with links to all of the components that you can refer to if you decide to enter the hobby and want to duplicate what I’ve built. 

Maintenance Tasks

Once a system is established, there are 4 basic tasks that must be routinely completed to keep a tank stable and its occupants healthy.   

1) Routine Water Changes

2) Making sure RODI (Reverse Osmosis / Deionized) water is always available

3) Topping off with fresh RODI Water to maintain salinity

4) Making up fresh Salt Water and doing routine water changes

These four tasks take up over 90% of the time needed to maintain your tank, and these can all be automated easily.  Cleaning, sock changes and minor equipment maintenance are other tasks that are easy to handle if the system is well designed. 

Automation Benefits

I can leave my tank unattended for about 2 weeks with no human interaction or the need for a neighbor or a friend to come over and do anything to the system.  What gives me peace of mind when we do leave for extended periods of time is the fact that I can monitor all of the system parameters via my tank controller, (which I’ll describe later in more detail) as well as visually from my iPhone using an Eve Cam (shown below). I’ve have an Eve Cam set up inside of my sump, as well as externally to see the display tank. I’ve found these to be very reliable, even in the salty environment of the sump. I’ve had the same camera in the sump now for about 4 years and it still working with no issues.

Saltwater or Freshwater?

I’ve always been a fan of Saltwater over Freshwater for home aquariums.   They have held my interest and kept me in the Hobby for over 30 years.  The fish and the ecosystems are much more interesting, diverse, and in my opinion, more beautiful providing an attractive decorative addition to your home that becomes an awesome conversation topic when you have guests.   

Is saltwater more difficult, maybe a little, is it more expensive, yes, but not that much if you plan accordingly and you are serious about entering this hobby.  Especially if you plan on starting out with fresh water, then “advancing” to saltwater.  Why incur the expense of freshwater system components that aren’t needed or are not appropriate for a saltwater system.   With the technology that exists today, starting out with a saltwater tank is not the overwhelming challenge it was years ago. 

Fish are Pets Not Decorations

I used the term “decorative” addition to your home, and it absolutely is,  but these are live animals, and you need to think of them as pets, just as you would a dog or cat.   Fish keeping should be an educational endeavor and thought of in a conservationist light.   It’s important to learn about this ecosystem and teach those around you why we need to care for this critical resource.  Treat them with all the love and care you would with any household pet.

FOWLR or Reef

While my opinion is to dive right into starting a saltwater aquarium vs freshwater, attempting a reef tank (with live corals) vs a (FOWLR) Fish Only With Live Rock tank is a terribly bad idea.  You can do all the research you want, but a pre-requisite to keeping live corals is mastering basic saltwater aquarium techniques, you need to practice!  If you would like to advance to keeping live corals, then by all means do the research and purchase a system that will be capable of becoming a reef tank.  A reef-capable system can always be just a FOWLR tank, but the opposite is not always true.

LOCATION-LOCATION-LOCATION (The secret element for long-term success)

Picking the best location for your system is critical for many reasons, but if you really plan properly to allow for great automation, the benefits are significant.  The most common factors that all advice articles will discuss are the following: 

  1. Pick a location that can handle the weight of the tank factoring in the weight of the water
  2. Choose a location that does not see direct sunlight, this will cause algae problems
  3. Make sure you have access to a GFCI Outlet, preferably a 20 Amp Circuit
  4. Pick a location that provides ambiance to a room that you actually spend time in.

These are prerequisites of any aquarium, however, there is one more extremely important element to consider.  If at all possible, pick a place where you can have access behind the wall where the tank is located.  If you find a location where you can build a small “Fish Room”, this will enhance your automation capabilities immeasurably!

The Fish Room!

I currently have a 90-Gal FOWLR system shown below.  I recommend the complete Red Sea Reefer XL425 System.  It’s a complete system that comes with all the necessary components to get started (Sump, Skimmer, heater, lighting, return pump) so you don’t have to research, specify and purchase all of those components individually.

The two pictures above illustrate how I picked the location: The picture on the left shows the aquarium located in my finished basement, in a location that receives very little ambient light.  It’s also located where we spend a lot of time, so we get full enjoyment out of it and it’s a great conversation piece.  It’s on the basement floor, so weight is not an issue, and finally, I was able to install a 20A GFCI circuit prior to tank construction.

The picture on the right is the opposite view from our storage room.  I was able to open up a small space (6ft X 4Ft) in our storage room directly behind the wall where the tank is located (See Below)

A 4ft x 6ft space is more than adequate to handle all of the equipment needed for full automation that’s not possible under the tank in the sump area, and if configured properly, allows you enough space to work in the room to do testing, equipment maintenance and cleaning.

As I mentioned, the Red Sea system I recommended above comes with all of the necessary equipment needed to build a workable system, but it will be manual.  This article does not go into detail on the Skimmer, Sump, Pumps, Heater, etc since those instructions will come with the system.   However, let me walk you through all of the required additional components in the “Fish Room” for complete automation to create a very low-maintenance aquarium.

Sink and Drain

I have a small utility sink with hot and cold running water, this is an absolute necessity.  Not only is it important from a convenience standpoint to do tank cleaning and equipment maintenance, but it’s also the drain location where you can direct the rejected water from your RODI System.  Since this install was in the basement below grade, I had to use a pump-up system to pump the water up into my sewer lines.    The exact pump I used is the Simer 2952B Self-Contained Above Floor Corrosion Resistant Sump/Laundry Sink shown at the bottom left of the picture below.

RODI System

This is another absolute necessity for saltwater systems.  Tap or even well water is just not good enough.  Dissolved solids and chemicals such as chlorine or chloramines are killers for all sorts of reasons outside of the scope of this article.  Trust me, and virtually any experienced aquarist will tell you, get a multi-stage RODI system to ensure your top-off water, and saltwater makeup water does not contain any dissolved solids (0 TDS – Total Dissolved Solids). 

Here’s what I’ve used for years, and is currently installed in my fish room, The Spectrapure MaxCap RO/DI System. It has a capacity of 90 gals per day and has been a reliable unit for me for almost 10 years with several tanks I’ve owned.

Typical household water pressure is usually not adequate to run your RODI System at the appropriate pressure, so I’ve also installed a booster pump.  This link is not the exact pump I’m using, however, the Geekpure RO Booster Pump Kit is an excellent alternative.

If you have city water, your municipality in all likelihood is using Chloramines in your water supply.  You RODI system may not remove these completely, and trying to collect RODI water and chemically treat it is challenging, I’ve even experienced issues when trying to use a chloramine cartridge in one of the stages of my RODI System.  When I started the system illustrated in this article 4 years ago. I had an extremely difficult time starting the cycle due to the presence of Chloramines.  I finally found the answer with the “Chloramines Monster.   For peace of mind, I highly recommend investing in this unit from Bulk Reef Supply.

Bulk RODI and Salt Water Storage

This is another important key to a long-term, low maintenance system. The bottom left of this pictures shows (2) 33 Gallon Brute Heavy duty trash cans.  These are the ideal size for an aquarium of this size.  The workable capacity in these cans allows you to make up enough salt water for about 3 weeks of automated water changes.

Both tanks are connected together with ½” Schedule 40 PVC piping using Standard ½” PVC Bulkhead fittings for penetrations and connections. You need about 20 ft of ½” pipe along with couplings, elbows, valves and bulkhead fittings to configure this system.

The tank on the left above is the RODI storage tank and shows the detail of how it’s configured.  It has an Eheim 600 Universal submersible Pump located at the center bottom.  The internal piping allows for the tank to simply recirculate, but there’s a ½” PVC ball valve in the circulation loop inside of the tank to create back pressure so it will either flow out through a nozzle to fill a container or pump directly over the saltwater tank to make up saltwater based on valve position. 

The RODI tank always remains full as it’s on automatic Level control, so RODI water is always available.   The level is controlled via an electronic float switch, using an I/O Breakout Box Module which is monitored by the Apex Neptune System.  When the level drops and the switch opens, the Apex system turns on the Booster pump, and opens a 120 Volt solenoid to allow water to flow through the RODI system.  There is redundancy for safety if the electronic level control fails, a manual float switch is also installed that will physically shut the system down to avoid overflows. 

The tank on the right is the bulk Saltwater makeup tank.  The internal piping is configured similarly to the RODI tank with an Eheim 600 submersible, however, the pump in this tank is used primarily for mixing of new saltwater.  While the back-pressured re-circulation loop will allow you to fill an external container, there are not many occasions when you need to do this as the auto water changes come directly from this tank (discussed below).

The configuration of the bulk RODI and Saltwater system may sound complicated, but it’s not.  If you have any detailed questions, leave me a comment below and I’ll answer any questions you might have.

Auto Top Off and Auto Water Changes

The reason you want to locate a room directly behind the wall of your tank is for Auto Top Off and Auto Water Changes directly from your Bulk RODI and Bulk Saltwater tanks.   As far as water changes are concerned, I haven’t done a manual water change in over 10 years with my last two systems.  The system does daily small water changes using the Auto Aqua Smart ATO System.  This is a slick, simple unit that comes with 3 micro pumps, one goes directly into your bulk RODI tank, one goes directly into your Bulk Saltwater makeup tank and one goes in the variable level section of your sump under the tank.  You run the tubing through the wall from the RODI and Saltwater makeup tank to your sump, and the tubing from the micro pump in the variable section of the sump is run through the wall back into the fish room into your sink.  

There are also 2 optical level sensors that you place in the variable section of the sump.  When the variable level of your sump drops below the optical sensor, the micro pump immediately adds fresh water directly from your bulk tank.  This top-off only takes a few seconds and occurs around the clock a few times per day keeping your salinity perfectly constant.  Every time the auto top-off adds water to your sump, the level switch in the Bulk RODI tank senses it and tops off the RODI tank via the automatic level control monitored by the APEX Neptune.  You never have to worry about refilling your auto top-off reservoir or making up RODI water. 

As far as the daily water changes, I set the system to do them every 24 hours.    The amount of water that is changed is determined by the difference between the top optical sensor in the sump and the lower.   You can play around with this, but on average, I’m changing about 13% of my system volume weekly in daily small increments.  My nutrient levels (Nitrate and phosphates) are always non-detect.

I feed a variety of frozen foods, however, when I’m away, I use the Apex Neptune automatic feeder and feed dry food for those times when we are not home for a longer period of time. 

So that’s it, this is basically an overview of the system that allows me to have a maintenance free system for about 2 weeks.

Please leave your comments below or any questions you may have, I’d be happy to answer them.

If you do decide to move forward with this system, please use the links in this article.  They are SAFE affiliate links that do not cost you anything extra if you go through them, but it does provide a small commission that helps fund this blog. 

Happy Fish Keeping


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