# Overflow & Pump, how strong should pump be?



## AndyGB4 (Dec 17, 2012)

Hey guys, I'm sure this subject has been done to death, but I read just about a million threads on a million websites and I just can't wrap my head around this issue.

So the tank I'm using was bought pre-drilled with an overflow already installed, and the pump was also included in the purchase. 

I'm pretty sure the overflow is 3/4". 
And my pump is a EHEIM compact+ 2000, 264-528 gph (US).

I'm still learning everything to know about saltwater tanks, so I'm bit a confused here. 
How strong am I supposed to set my Pump to? 

Because when I play with the overflow pipe's ball valve _(i think that's what it is, new to plumbing!!)_, and with the Pump's power, the water level either eventually gets too high (risking overflowing the DT), or the overflow pipe makes these weird gurgling noises.

Can you guys point me in the right direction? Should the valve be fully opened? Should the pump be on the strongest level too? My tank is a 40g DT and a 20g Sump, so how should my gph from my pump be?

Sorry for all the different questions, but I'm really lost here! I hope you guys can get me back on track! (i can take pictures of the plumbing and pump if that helps)

Thanks!


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## Reefing Madness (Jun 26, 2011)

Might want to set the pump for around 300-400gph. But, whats going to happen is this, you cut back on the pump so your DT doesn't overflow, the water in the overflow will wait all the time for water to be refilled by the return pump, thus making a little bit of noise.
Did you actually turn everything on and leave it alone for a few minutes for observation?


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## AndyGB4 (Dec 17, 2012)

Thanks Reefing, 

So by doing that, the noise you're talking about is kind of like flushing sound, right? Which I'm guessing is the sound of the water going down the pipe with the air trying to come out through the top of the pipe? 

Anyways, as it stands right now, I've left it like this for over an hour, and it's been making that noise about every 2 minutes i think. The overflow pipe is opened fully,
and the pump was on the minimum, so I guess around 260 gph.

I can't remember the different amounts I've tried so far, but I did a lot of trial and error and couldn't find a proper medium. So I left it at 260. Ill try putting it between 300-400 and see what happens.

Also here's 2 pictures of the overflow, is that where the water should be or should it be different?









^ You can see the air a bit lower than water level here, is that normal? ^


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## AndyGB4 (Dec 17, 2012)

At 300-400 gph, it's making the flushing sound almost every 5 seconds. basically you see the overflow box have air lowered into it (or i guess it fills with water and then the water gets drained?). And obviously, there are tons of bubble (big and small) that are coming out of the pipe in the sump.


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## Reefing Madness (Jun 26, 2011)

Ok, now I see what we have here. Not the Overflow I was thinking. Couple ways we can try to stop this. I don't think you want the pump at full flow.
Would be better is we had a bigger overflow box, we could ge a Stand Pipe set up going in there.
Other would be to get an airline on the top of the pipe going down, to allow the air an escape.


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## AndyGB4 (Dec 17, 2012)

Ya the depth of the overflow box is less than an inch. It's pretty small.

If I would get an airline, do you know where I can find instructions for that?

So from what you're saying, the problem is that the air can't get out of the tube properly?


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## Reefing Madness (Jun 26, 2011)

Yea, air gets trapped in there, then builds up, then the water kinda grabs it and runs it down, making that noise.
DIY Overflow Using Only PVC Pipe (DIY OVERFLOW PROJECTS)


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## AndyGB4 (Dec 17, 2012)

Thanks Reefing!

Tomorrow after work I'll pass by Home Depot and pick up the barb fitting and the airline tubing as well and I'll give it a go!

Is there specific part of the pipe i should puncture? I know it will be on the top of the Elbow piece going down, but do I put it at the back of the elbow (above where the pipe goes straight down), or do I do it before that part, where the elbow is still going horizontal.
(by the way, there's no visible pipe between the bulkhead and the elbow, the elbow seems to be attached directly to the bulkhead)


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## Reefing Madness (Jun 26, 2011)

Right on. I'd put it center of the elbow.


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## AndyGB4 (Dec 17, 2012)

So I tried one last time to regulate the overflow and the pump, and it's been running all day, and I haven't heard a sound yet!

So it seems like I found the right amounts I need. The overflow is almost fully opened, and the Pump is set at about 3/4 its capacity. So I'll probably just leave it as is.

But I did take down everything I need, if I wanted to drill it. So I'll be ready if the need comes. 

As usual, thanks for all the help Reefing!


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## Reefing Madness (Jun 26, 2011)

Right on. Good stuff. Glad you got it without mods.:-D


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