On my last three tank builds I have built my own aquarium sumps out of old aquariums.
I made one out of a 55 gallon aquarium for my 125 and now I use a 120 gallon aquarium
for my new 240 gallon tank. I also just built a 40 breeder aquarium sump for my
clownfish grow out system. Please click on the pictures below for detail design
guides on how I built these aquarium sumps.
There are many advantages of having an aquarium sump on a saltwater aquarium. It
provides a place to put your return pump, skimmer, heater, probes and other equipment
while adding to your overall volume of water in your system. An aquarium sump can
be is simple as a plastic tub to a custom acrylic aquarium sump. These pages will
discuss designing aquarium sumps as well as show of some that I have made.
The first thing to determine is what size do you need. It will depend on what size
your main display tank is as well as what equipment will be in it. Things like if
you are going to have a refugium in the aquarium sump, the size of the protein skimmer
and what return pump is being used. Generally I recommend a sump that is approximately
half the number of gallons of the display tank. For example a 75 gallon tank should
have a 30-40 gallon aquarium sump. I prefer to be on the higher side if possible.
The next thing is to decide what material should be used. Acrylic and glass are
the most popular. Personally I prefer glass tanks. Used glass aquariums are inexpensive
to find used and you can get glass cut at most local hardware or glass shops to use
for baffles. For example I found a used 55 gallon tank for $10, bought $30 in glass
and $10 in aquarium silicone and had a custom glass aquarium sump. Acrylic sumps
are nice but the materials tend to be more expensive and if you do it yourself cutting
the acrylic can take a lot of time. Custom acrylic aquarium sumps can be made but
the tend to be expensive. The choice is up to you but I prefer glass aquarium sumps.
How to layout the aquarium sump baffles?
Laying out the baffles can be a little tricky. It can be really simple or really
complex. The first thing is to determine how many chambers you need. You may want
one for the protein skimmer, one for the refugium and one for the return pump. Typically
I design the sump so the protein skimmer and refugium chambers water level does not
fluctuate. This can be done by the height of the baffles. Lets look at this simple
3 chamber aquarium sump. It will only require three pieces of glass to make.
In this design the water enters the aquarium sump into the skimmer chamber. The
water then flows over the second tallest baffle into the refugium chamber. It then
flows over the third tallest baffle. On this baffle I sometimes put silicone in
some egg crate on the top of it so the macro algae does not float over the top of
the baffle. As for the height of the tallest baffles I typically start at 75% the
height of the aquarium sump. If the height of the sump is 12” the tallest baffle
would be around 9” tall. Once thing to remember is that the sump needs to hold all
the water from the display tank that may back siphon in a power outage. This can
be calculated. Click here to see how to calculate water volumes. The height of the
second tallest baffle is typically 1-2” shorter than the tallest one. This is dependant
on the width of the second tallest baffle as well as how much flow is going through
the sump. Typically for higher flow I would use 2”, lower flow you can use 1”. If
you are not sure I would go 2” to be safe. The skimmer and refugium chambers’ water
levels do not fluctuate but the third chamber where the return pump is will.
How to prevent micro bubbles in the return?
The best way I found is to keep to prevent micro bubbles is to keep the return pump
as far as you can from the last baffle. If you look at the above sump design the
water has to go around a corner and then the length of the aquarium sump to get to
the return. The water will be pretty calm by the time it gets to the return pump.
I have never had micro bubble issues with this type of design. Some people use
bubble traps. This can work well but I do not like vertical style. See picture
below of a couple of different types.
This is a vertical baffle design water flows over and under a couple of baffles to
help trap bubbles. If these baffles are not designed correctly micro bubbles can
be a problem.
This is a horizontal bubble trap design. It basically makes the water travel farther
before the water gets to the return pump. It tends to use less glass as the vertical
bubble trap and in my opinion is easier to build.
In the future more complex sump design will be added. The above information is a
good place to start with the design of your own custom aquarium sump. Whether you
decide to do it yourself or to have one custom built a well designed aquarium sump
will be a benefit to your aquarium.