Water movment through sump


Reefing newb
Ok, I have not started setting my tank up yet but I have been collecting things while researching and getting things ready. I have the tank, which is a 150 gallon tall, and I have already built the basic framework of the stand. I plan on a sump with a refuge and probably a skimmer.

I currently have about 95 lbs of dry base rock and will be adding probably 60 to 75 pounds more before I start putting water in the tank. I will then add a few pounds of live rock to seed the dry rock in the tank. I also think I may put some dry rock in the sump as well, but I have not decided that yet.

I plan to have a couple power heads in the tank to create a flow that turns the water over 4 to 5 times the volume of the tank, so anywhere from 600 to 800gpm in the tank. How much do I need going unto the sump and back to the tank then?

I have been reading where some folks are putting massive amounts of water though the sump, are they just using the overflow and the sump return to create the flow in the tank? Should I really need to move 4X the volume of the tank though a sump, if I have plenty of flow around the LR in the tank? I know that the bacterial filtering is done by the LR once established, and the sump is used for mechanical filtering and a place for pods and such to thrive. Would I be OK with say a flow of 100 gallons per hour into the sump or do I need more?

And before anyone ask, no, it is currently not a drilled tank. I do plan on doing some drilling but it will probably be in the back glass and not the bottom. The tank is an Oceanic and I have read that on some tanks they used tempered glass on the bottom but it depends on where it came from. I can't test the glass right now as it has my fresh water fish in it right now, due to having to move them to replace the carpet in the house. I am building a new stand for the 55 right now and as soon as I am done with that, I will be putting the Cichlids back into the 55 and then starting on the saltwater build. (No, I have not put any meds into the tank since the Cichlids were moved into the tank, so no copper issues.)

If I can drill the bottom then I will do it that way, but for now, it looks like it will be the back of the tank that gets drilled. I will not be able to put my tank right up to the wall, but since I am building the stand myself, I will just have to made sure that the back part of the plumbing is covered up.

Tim Sapp

The bottom is almost always tempered glass. You can look at the side with polarized sunglasses to tell whether or not its tempered.

I had a 150T with a HOB overflow and never had an issue with it.
+1 erin, look on youtube, polorized sunglasses and a smart phone. Awesome trick. I hve a hob overflow with 660gph flow, the water flowing down the tube is kinda annoying, but so am i........ Ive got a low flow sump/refugium and it is no where near river rapids threw it. If you run 150g into your sump, that would give you 1x per hr from your dt, i honestly wouldnt want to run that low but your decision. Its seems with overflow boxes, it is a chance of heavy particulates get in there and i tend to stir up my sand bed several times a week, but my 7in sock seems to be dirty every 3 days. So what i am saying is again, make sure you size your sump accordingly, i would want to oversize just so i dont have to rebuild.. good luck if you understand my babble
In your sump I would recommend 3-5x turn over rate. I run 4x through my sump which allows my protein skimmer to do its job. In your display tank depending on what you plan to keep 10-40x turn over rate. You want to make sure you don't have dead areas in your DT. I have my mixed reef around 40x turn over.
OK, so thanks for the info guys, it looks like I need to plan on having more water through the Sump. If I don't have tempered glass on the sides I am going drill them and add an overflow box inside the tank.

As you can see from the photo below, the top of the tank not only has a cross brace on the top, it has a framework of glass around the top.


This makes me not want a PVC overflow and I can't have a HOB overflow because the tank has the 4" of glass which makes everything have to move in so far. If I can drill the back glass of the tank, I can then add a small internal overflow box over that part of the tank, so I can hide bulkheads and make sure no fish get sucked down into the sump.

Now I just have to figure out how big to make the drains. Seems like most of the drains I see on other tanks are SOOO big. I may put in two drains and two returns with plans on only using one of each for now, with the ability to add the second ones if I decide I need more movement.

I had a euro-braced 150g tank like that one time but it was manufactured with holes in the bottom and a built in overflow. Just make sure wherever you drill the glass isn't tempered.
Most all of your flow inside the display tank will be created by power heads to get that multiple times turnover rate. You will also have some flow created by your return pump. You just don't want it to look like the ocean in your sump:mrgreen:
No crashing waves in the sump or stagnant pools. You want your return water to spend a little time in the sump hence the 3-5x turn over. This allows your skimmer to do more work before the water returns to the display. The display tank is where you want the high turn over of flow 10-40x per hour which you can achieve with power heads plus what your return pump adds.
If you still plan on drilling, a good site to get an overflow kit is Glass-holes.com. They have kits to suit just about every flow rating and it even comes with the correct glass holesaw.
If you still plan on drilling, a good site to get an overflow kit is Glass-holes.com. They have kits to suit just about every flow rating and it even comes with the correct glass holesaw.

Thanks, that is actually something I was looking for. I'll be ordering from them soon.