A sump can do a lot for your saltwater aquarium.  It provides a place to hide all of your equipment,  and it increases your tank’s water capacity.  Two very important things when you want to have a nice display reef aquarium  but when designed correctly it can also be a place to trap detritus, filter your water and cool your saltwater aquarium.  I use a simple sump on my 46gallon bowfront aquarium and this article explains how it is done.

The way my sump works is that water from the main tank overflows into a CPR overflow box that is pictured above.  The water then flows down a 3/4″ vinyl tubing into my ten gallon tank in my stand.  I use a powerhead to keep bubbles from being trapped in the CPR’s U bend. When deciding on an overflow box it is important to choose the correct return pump that will not exceed the gph that the overflow box can handle.  Now if you bought a reef ready aquarium then you wont have to worry about an overflow box flooding or cleaning out an overflow box.  On that note, I have been using the CPR style overflow box for over five years without any mishap.  There are many other kinds of overflow boxes but that is for another blog.

The water from the main display aquarium rushes into the overflow box and down into the vinyl tubing you see on the left hand side of the above picture.  I currently do not have a refugium but in the past I did have one on this tank. It used to be sectioned off where the water comes in the sump.

When the water reaches my sump it hits a filter bag filled with carbon, this reduces the amount of bubbles, saltwater spray and keeps the carbon moving.  It also catches detritus which is important when you have a bare bottomed aquarium.  In the sump I also have my phosban reactor, a glass thermometer, heater, skimmer, and a Mag 5 return pump that is hooked up to a SCWD.  It is essential that I keep a nice quite system so by resting my overflow line and my return line on sponges it keeps down any hum or noise that may develop.  I also have installed a smaller piece of tubing on my overflow line to keep out air pockets.

I currently use an Aqua C Remora protien skimmer (not the best but it does the job). It is a hang on back or hang on tank type of skimmer.  It works equally as well on the sump or on the main display tank.  I prefer to have as much room in my main tank for fish and corals and for aesthetics, so it is placed in the sump. The return of the skimmer pours out onto a plastic knitting sheet, If you have never seen one it is white plastic with openings about this [ ] big all throughout the sheet.  This helps the water from splashing and aerates it at the same time.  This plastic knitting sheet is placed in a tupperware container that is drilled with holes. I also have a bag of Purigen in the tupperware container so that when the water from the skimmer flows onto the plastic knitting sheet it goes right over the bag, keeping the Purigen moving.

Overflow Rating vs Return Pump

The return as I mentioned before is a Mag Drive 5 pump that has a Max gph of 500.  My CPR overflow box is a cs50 which has an overflow rating of 300 gph, this means that when the CPR overflow box exceeds 300gph it overflows the box and you have a nice saltwater enhanced floor .

So then how do I get away from using a 500gph return pump?  Since the Mag Drive pump pushes water through a SCWD it causes a small amount of friction and the water losses some of its momentum.  The Mag Drive also has a head loss when pumping water straight up, At four feet the Mag Drive only pumps 310 gph.  As the water reaches the top of the tank there is a little more friction as the water is pushed out of two directional U-Tubes.  When all is said and done I estimate that the pump eventually pushes 290gph or a little less.

Here is a couple of Videos on how a sump with baffles is created.