Setting up sump for first time

HeavyWater247

HeavyWater247

New member
Trying to get a sump setup and am running into a little issue was wondering if any vets could chime in on. So my 36gal bowfront, running into a 20 gal sump. HOB eshopps nano overflow box. Return pump is a cobolt aquatics mj1200. I know the flow rate and over flow should roughly match or at least the return a little more. I have everything hooked up but i'm noticing the pump is kicking up more water than is draining into the sump. I start the siphon via airline tube, and water is draining albeit slower than what i would expect but then again, i've never really seen a working sump up close. As the water is sort of draining, the pump is filling up the tank almost to the top so I have to unplug the pump, wait till the reverse siphon takes the water level back down until it breaks on the outlet. I'm trying to figure out if, i need to control the rate of return on the pump, something is wrong with my drain/siphon or something else. I did notice that there is an air bubble at the top of the u tube going to the over flow but i still see the water draining out/see it coming out going into the sump. From what i've read, the nano has a flow rate of ~200 gph and the mj is rated at 295 gph. Should I use a valve to restrict return flow or is my overflow wrong?

Thanks in advance.
 
Going bigger for return pump is the right thing to do because you can back it down if needed. Too small of a pump and your screwed and will have to exchange or buy another pump. Get a gate valve so you can adjust the return pump. I had to do the same thing with my 75g.
 
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That bubble in the u tube is the reason the overflow box isn't working. You need to insert a piece of airline tubing into the top of the u tube and suck out the bubble. Once the bubble is gone the overflow should be able to handle more flow.

The flow rate you state is with zero height. Since you are pushing the water vertically, the flow rate will be much lower. The problem with low flow is that any air bubble that gets pulled into the overflow will end up getting stuck at the top of the u tube and gradually will prevent the overflow box from keeping up with return pump. That's why a return pump flow when pipe resistance and height of the return outlet are factored in.

HTH,
 
cool...makes sense. I started/stopped it a couple of times, seems like the water is overflowing fine but i think the pump is pumping too much water for the drain to keep up...when i leave it on, i can watch the tank fill and if i don't unplug the return pump, looks like it will over flow the display tank.
 
yeah, what i ended up doing was lowering the internal overflow box (the black one). Once I did that, the water pushed right out of the u tube.
 
I had a similar setup with my 75g. I had an external U-Tube overflow that I had to tinker with to get it going. Hope this works out for ya.
 
Thanks. Rocket, that's how I started the siphon initially. The water comes up and then flows over the inside of the bend. Doesn't seem like there is enough pressure to fill the tube completely. The inlet side of the tube fills then flows over the bend but not enough to "fill" the tube. The exhaust end of the tube fills up but not completely to the point where there is no air per se. I drew a rough sketch of what it looks like. Not sure how to increase the flow, putting a bigger pump in the sump, in my mind would just mean that the display tank will fill quicker thus causing me to shut off the pump faster or else i have a wet floor. I'm thinking the issue is stemming from the siphon velocity/amount which is being affected by the overflow setup somehow.

The little swirlies on the left of the tube is where the water basically backs up to.

utube.jpg
 
So Rocket, what your saying is that if I have a bigger pump, it should eliminate that pocket thus increasing the output of the overflow?
 
So following along Rocket's advice, i dropped the black internal overflow box basically leaving the tube in the water by itself. I then hooked up a powerhead with a piece of hose attached to it and shot the output up into the inlet of the u tube. It cleared out the tube initially but then a rush of water plowed through, filling the tube completely. Man, there is such a big difference in water flow. Now my output is matching the input of the pump and the water level is steady with no drop/rise in the display tank. Thanks to all for the assistance. Guess just need to figure out how to do this again easily should my siphon break with out having to drop the box....i'm guessing that's what a lifter is for?
 
The aqua lifter is what kept the siphon on my overflow going. I had a back up just in case the one went bad. It kept air out of my overflow. If you have the ability to add one do so to keep the air out of the tube.

Do not get a bigger pump. If your overflow is 200gph and your return pump is 295 with 3.5ft of head loss then your GPH should be roughly 259 give or take an elbow or 2. This should work fine. I would also, just to be safe, add a gate valve just in case you needed to adjust return flow for some reason.
 
HW if you get a short piece of air line and jam it up to the spot of air, suck all the air out and the last remaining bit gently tap on the U tube to make bubbles tiny they should flow out. Also keep your black box low enough to keep a good flow thru it. It if likes to work with box low leave it low. But get a gate valve or a ball valve on the pump side to control flow into the tank as a bare minimum. A gate valve is a nicer fine adjustment then the ball is but sometimes harder to find.

I was working on an idea of putting a second return line on my HoB overflow just as an emergency over flow. But that's another story.
 
BlindZide said:
The aqua lifter is what kept the siphon on my overflow going. I had a back up just in case the one went bad. It kept air out of my overflow. If you have the ability to add one do so to keep the air out of the tube.

Do not get a bigger pump. If your overflow is 200gph and your return pump is 295 with 3.5ft of head loss then your GPH should be roughly 259 give or take an elbow or 2. This should work fine. I would also, just to be safe, add a gate valve just in case you needed to adjust return flow for some reason.
Click to expand...
This is going to be the best bet right here. This is exact what I had to do back in the day. The aqua lifter will keep that little pocket of air from coming back. Which it will inevitably do.
 
cool...thanks for all the feedback...gonna go the lifter route. Will definitely make sure I go drilled on my future/larger tank :-)
 
You will learn so much about your tank messing with the hob overflow and u tube. What i learn about them is that i hate them! Pain in the aasss everytime the flow breaks...not to mention the noise. If you plan on being in the hobby for a long time, get yourself a tank with an built in overflow (reef ready) in the future. Good luck!
 
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