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.
I am brand new to salt water aquariums. I currently have a fresh water 55 gl aquarium that I want to convert to a reef aquarium. I think a sump is a good way to go, but I’m overwhelmed by all of this. Any recomendations on where to start? I could make my own sump, I have at least 8 extra aquariums ranging from 2gl to 30 gl.
Building a sump can be very confusing at first. The best thing to do is read all that you can about it.
A 30 gallon sump would be good on a 55 gallon aquarium. What you need to do is figure out how the water from your main tank is going to flow into your sump. Once the water is there you need to match your return pump, the pump in the sump to what your overflow rate can handle. You can use an overflow box on your main tank to get water down to the sump or you can drill your main tank.
Here is a link to a couple of videos on sump design.
http://www.brettsreef.com/index.php/how-to-build-a-sump-with-baffles/
I have a question about sumps that may be a little strange. I’ve been looking for a new tank for my Cichlids and found a one that had a sump with it on craigslist. Stand looked great in the pics I had, owner said it was like new.. drove the 200+ miles to take a look, and it turns out that the stand had bad water damage. Mainly on the floor of the inside, and on the inside of the doors. Is this typical of stands with sumps in them ? Are there precautions I should take when running a sump to prevent damage of the wood from water evaporation / etc…
Thanks for the help !!!
-Ton y
Hi Tony,
In my experience with saltwater sumps and refugiums there should be very little to no water damage where your sump is located if the sump was installed correctly the first time. If the sump had not run correctly when first used you could result in a small amount of overflow or leaking plumbing, it happends.
From what you describe it sounds like the seller had a major leak in plumbing, the main tank or he had overflowed the sump a couple of times. In either case if he had cleaned it up there should be only minimal water damage. I would ask the seller of the stand why there is so much damage.
If you want to prevent having the above problems then make sure you fit your sump and overflow with the correct flow ratings, It helps to put some sort of pvc flow valve in the return line to tone down your return pump if it is rated above what your overflow box/line is rated.
Another helpful hint is to install siphon breaks in your return lines so that when your power goes out your main tank wont gravity feed water into your sump.
I have a question. I am really new for the reef tank, but I’d like to build my own sump, and don’t know how. I’ve watched a movie clip from your link above, I had some ideas and know how to do it. I gonna buy a tank 215 gallons w/reef ready. I don’t understand that much about the water flow down from the main tank to the sump. how do I know how many gph of water flow from the tank to the sump? then I’ll know the rate to get the return pump.
The reef ready has 4 wholes, 2 on the left and 2 on the right. which one is for water flow and which one is for return pump.
This might be a stupid quetsion, but I am learning, and really need to build one. Please explain me more detail. Thank you so much!
Hi doug welcome to brettsreef.com,
When you buy your new saltwater tank you should take a look at what the overflows can handle, The manufacter of the tank or the overflows should give you some direction on how to hook it up so that it works effectivly.
Since the tank you are talking about is the reef ready 215 gallons then I suspect its the Oceanic model which has Two mega flows, These mega flows can handle 600gph each. This is a lot of flow so you will need a decent sized return pump, I would say one rated between 1500-2200gph (depending on how low your sump is). Keep in mind head loss and plumbing friction to determine what sized pump you will need.
Two holes are for return (one left and one right) and two holes are for the overflow to the sump. You would want one hole on each side for the sump overflow and one hole on each side for the returns. So when you do your plumbing keep in mind that you need to have two return lines or a Y in the return line, This is also true for the water going into the sump, but for simplicity sake and for safety is may be better to keep the two sump lines seperate from one another instead of Y’ing them together.
Thank you so much for your help. I know how it works now, but i am still having another question. As your explaination above that you recommend me to do two return lines. I don’t get this. You mean i do 2 separate return lines with 2 return pumps or just one, and connect it with T connection or what are two lines instead of Y? Thanks.
Hi Doug,
What I meant was that you would probably want one pump with a T connection so that you essentually have two lines running to the main aquarium from the sump. You can use a SCWD (a wavemaker device) to accomplish this. A SCWD is not neccasary but it adds more random flow to the aquarium.
Ok now this brings up a new question for me.I have the tank he is talking about.2 built in overflows with 2 lines in each.The guy that instaled my tank put both drain lines in the sump with no tee.Then he only hooked up 1 return line and left the other just sitting in the sump.question #1 is this ok?question #2 was I want to put a refugim in but have no room in my sump,you would have to see it.Can i put in another sump and run 1 side with no skimmer and just the refugim and basicly have 2 systems on my 1 tank.I didnt know if 1 would flood the other.my idea is it would add more flow and help feed the reefs,not to mention add more filter.I am brand new to salt so please help.Also if 1 pump goes out would it flood?The guy said I have some kinda safty system so if the power goes out it wont flood.I my self have powered down the system and it does fill the sumps but stops before the tank floods.Man thanks for helping people for free.I wish there were more people out there that felt they could give a hand without expecting somthing in return.
Hi Steve,
Having two drain lines going to the sump is ok, you wouldnt want to T off the drain lines for a bunch of reasons, mainly noise and water back up.
The only reason I can see him not hooking up the other return line is maybe he thought that the pump may be to powerful for the overflows. Having one return line from the sump could cause friction and slow down the water coming from the sump… Not knowing what sump pump he installed makes it difficult to think of a really good reason though. Both return lines should be up and running, I would ask him why he did that.
Installing a refugium is a good idea for the benefit of the aquarium, It will increase your water volume and provide a place for pods, worms and other organisms to grow. You could also put a macro algae such as cheato in it to compete with other nuisance algaes.
You would have to research this a lot more to include it in your aquarium, since your aquarium is already up and running the easiest way would probably run another overflow from your main tank to the refuge and another return pump back to your main tank. Keep in mind that a refugium needs to have minimal flow to be very successful.
Thank you for your nice comments I appreciate them very much.
what is your opinion on the new marineland model#2 sump with the bio wheel (not the marineland tide pool ) ?????
also,i am buying a 90 gallon reef ready tank (fish only……i may possibly add live rock as well) should i buy the biggest sump that will fit in the cabinet, or just stick with the model#2 which is for tanks up to 150 gallons.
thankyou for your help.
Hi Michael,
My personal opinion is to skip over the marineland model #2 becouse of the biowheel. There have been some discussion that biowheels, over time will create nitrates. The main function of the bio wheel is to reduce ammonia and nitrite which in time will produce nitrate. Now this is a typical cycle that every fish tank goes through, however the bio wheel will continue to collect detritus and will continue to create nitrate. You will have to perodically clean the bio wheel which will then cut down its effectiveness in reducing ammonia and nitrate.
Using Live rock will cut break down ammonia and nitrite into nitrate. But you remove the nitrates with water changes. So then how is this diffrent from the bio wheel? You will have to do water changes anyway to remove the nitrate, while you are doing your water changes you suck the detritus off the rocks. Tank cleaners such as snails and crabs help remove detritus as well.
Another thing about the model #2 sump is that it lacks room for a skimmer, phosphate remover and any other equipment you dont want in your main tank. The shelves for filter media is a nice idea but you should really look into a phosphate reactor, these reactors utilize the filter media much better then any other system and you can use just about any type of filter media in a phosphate reactor.
The size of the sump matters…the bigger the better. If you are going with a fish only then go with the biggest sump so you will have a bigger water volume.
Hi,
I just came across your website material, and i wanted to ask you something concerning “uv filter”. I have a submersable uv filter, the lamp is in a container with hold tightly with a powerhead. I was just going through what you have posted, and after reading that uv filters kill both bad and good bacteria i am getting worried. I have been using a UV filter in my sump which contains an algea plant refugium as well and i have loads of propogating bacteria.
So, should i discontinue using a UV filter? maybe i have overlooked something you noticed when you said that “it kills good and bad bacteria”.
Please do advice.
I am a new to the larger salt water tanks. I have had a bio cube for a long time and I am finally going to a larger tank. Had the locals help me pick it out and advice for set up, but as I was watching the overflow and sump run last night and for some reason lost the flow on the overflow. I have an overflow and sump system similar to the one pictured above. My worry is that some day while I am work the overflow will stop and my sump will continue and overflow the tank. Any way to avoid this? Am I worrying about something I should not worry about?
Thank you for so many great posts and adivce.
M.H
Uv Lighting is not selective, meaning that it wont choose to kill only bad bacteria. It will kill good and bad. The main thing that Uv lighting is used for is for killing suspended algae which is why most successful small pond (Koi) owners use them. If your marine aquarium water has a green tint then its probobly good to use a uv light, if the aquarium does not have a green tint then you may want to turn it off and save some money.
Jeff,
Welcome to Brettsreef.com. Make sure that your overflow is not filled with air, If its a cpr overflow like the one shown then there is a nipple on the top of it that needs an airline house hooked up to it and then hooked up to a powerhead. Also make sure that you matched your return pump with the overflow. It almost sounds like your return pump is too big for the overflow you have.
wat is a siphon break. You said to put one in the return line to prevent water draining from the return line and flooding sump
Hi Callum,
A siphon break is a tactic point in your return line that some aquarists will drill holes into to prevent flooding.
I explain this process in detial in this post:
http://www.brettsreef.com/index.php/preventing-your-reef-tank-sump-from-overflowing/
Hi, could I connect two tanks with bulkheads?My 200gallon tanks stand restricts the area so only two small tanks can fit either side.
If I did this with a 6500lph pump is there anyway to know how big the pipework has to be (between the two sump tanks) so that one doesn’t overflow/run dry?