Overflow & sump???? What is it??

Question

What is an overlfow sump? How does it work? Is it needed? I am seriously confused, is it a good idea, what is the sump? Is there some type of media that needs to be replace? Is it a filter or does it just circulate the water?? Please help I am very very very confused?????????
~Confused Kyle

Answer 1

It's not absolutely necessary. What this does, though, is add "volume" to your tank and give you a place to hide equipment so it's not seen and it's kept away from tank organisms that may harm or be harmed by it.

You've probably seen overflows in pet store tanks, and just haven't realized what they are. The most common is where the tank is drilled through the back and a "strainer basket" is placed over the opening. This leads to pipes that drain the water into another tank beneath the main tank (this second tank is the sump). You can put filters, skimmers, heaters, macroalgae, whatever in it. You can consider the volume of the sump in with your tank volume, so instead of having your fish's wastes diluted by, say, 55 gallons (the main tank), it might be 75, if you use a 20 gallon for the sump. It can also keep your heater and power cords safe from animals like puffers that tend to chew, and also keeps small fish and inverts safer because there are fewer intakes for them to be caught in.

Another type of overflow sits in a corner and has a small portion of the tank blocked off. The top has openings through which water flows over, and the drill hole may be in the bottom of the tank in this case.

In either of the above cases, once water is in the sump and goes through whatever equipment there, it's pumped back to the main tank. The only trick to using these is to not fill the sump completely. If the power goes out, some of the water in the pipe will drain into the sump, so you have to account for that volume if you don't want a flood.

As long as the openings (strainers) to the overflow aren't blocked, your main tank shouldn't overflow. The entire system and flow rate is controlled by the powerhead or submersible pump used to pump water back into the main tank. As long as this water can flow freely downward, it keeps the top tank at the level of the overflow - either the bottom of the hole in the first type, or the bottom of the openings in the second.

As far as the sump itself, you can use it as a wet/dry trickly filyer (where the water coming in flows over bioballs or other media), as a refugium/algae scrubber (where plants care used to reduce nitrates, and small "feeder" organisms can be bred or bullied fish can recuperate), or just another tank on which you hang all the equipment you don;t like seeing on your tank.

It's also possible to put the "sump" part of the tank above the main tank, but not many people do this. Partly because it's not as easy to hide (it's not as convenient as they tank stand), but it has the benefit that more microorganisms can be "fed" into the main tank through gravity.

I should also mention there are "overflow boxes" that can be used to go over the rim so your tank doesn't need to be drilled.

Here are some photos of some sumps: http://www.flickr.com/photos/thayerz00r/508955279/ - complex
http://www.aquariumadvice.com/photopost/showphoto.php?photo=8618&cat=546 - complex
http://www.simplifiedreefkeeping.com/mello/leftside_sump.JPG - large sump in room behind a tank
http://www.aquariumadvice.com/photopost/showphoto.php?photo=6794 - simple

Answer 2

This is the sump fuge that I made for my 75gal. Reef tank.
http://www.flickr.com/photos/25717643@N00/1425398029/
The White hose going into the left chamber is water comming from an overflow box inside the tank, It then goes through a drilled hole in the back of the tank, through the white hose and into the left chamber.
The left chamber also houses a Protien Skimmer(you can see some of the crap pulled from the water in the collection chamber above the red knob)
It also houses a pump for the skimmer, Heater, and this is where I put a carbon bag once in a while.

The center chamber: Water flows over, under and over 3 baffles to reach this chamber.
This chamber is called the refugeium, it has a couple of inches of Live sand, live rock and tons of Macro algae, this adds a great deal of biological filtration and is a refuge to tons of small benificial organisms that would otherwise be consumed by the residents of the main display tank.

Right chamber: Water flows over another baffle into this chamber, It houses the return pump that pumps the water at high volume back to the display tank.
The pump also pumps SOME of the small organisms into the display tank where they become food for fish, Corals and so on.

I think it is a VERY good idea to have one, It is NOT nessasery but it does add a lot more water volume(the more the better), it is also a place to put some of your pumps and so on, so they are not in or on your display tank....
There is no media that has to be replaced unless you want to add carbon bags or any other chemicals.
Yes this one is a BIG part of MY filtration(refugeium, Skimmer)
It does circulate water and adds TONS of oxygen to the water.

It's very hard to see but in this pic, on the LEFT side of the tank, above the Green Torch Coral, to the left of the Red Brain coral (Mick Jager Lips.LOL), directly behind the round Black pump is the GREY overflow box, Water flows over the top of it and through the hole in the back of the tank, down a hose, into the Sump.
http://www.flickr.com/photos/25717643@N00/1425397637/