Problem matching overflow speed to return speed!

[bigbus]

I have a 110 drilled tank and a 25 gallon refuge/sump.

I filled it up with water these last few days and plumbed it but I ran into the problem of not being able to match the speed of return to speed of overflow.

I'm not sure what the speeds are but I have a ball valve on the overflow line to adjust it because at max speed the overflow goes a lot faster than the return.

I can tune it to be pretty close but I notice a difference in like 20 minutes or so that the level has changed.

Any body have an easy solution to this? I don't want to tinker with it everyday as it is a hassle.

[SaltyDr]

You want the overflow to be able to handle more than the return, that way you cannot overflow the tank. I'd say, let it rip. If you think that there is too much flow, I'd put a ball valve on the return, not the overflow.

[bigbus]

The overflow does handle more than the return.

When I have my overflow at max and the pump at max the sump will overflow. So I put a valve on the overflow to try to even it out. Just having a hard time with it.

The pump is already running max as it is. I turn the valve just a tiny little bit and the sump fills up, turn it just a tiny bit the other way and it slowly drains the sump. Just cant even it out.

[03LightningSVT]

Read all of this thread and you will completely understand the best method to solve most if not all overflow issues.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=1541946

Have fun:)

[mfinn]

You don't want to valve the overflow.

Figure out what the overflow will handle in gallons per hour, then use a pump that pumps less and you will be fine.

[bigbus]

Ok, I know for sure that my overflow handles more than my pump... because without the valve my sump overflows.

So.. the pump is already less than what the overflow puts out.

[bigbus]

From some things I've read, everywhere it says that the flow is dictated by the return.

But in my case, my overflow maintains constant flow no matter what the return is. I can dictate the rate of overflow by turning my submerged pipe at different angles.

My return pump is at max already so adjusting it lower will not lower my overflow. It would just suck water faster than the return is pumping and flood the sump.

[mfinn]

If the sump overflows, then there is too much water in the system.

[eric@tampa]

+1 on mfinn's reply,also get a gate valve instead of a ball valve...lot easier to fine tune.

[bigbus]

So that doesn't mean my overflow is draining too fast?

Should I open valve to full and pull water out?

[mfinn]

<a href=showthread.php?s=&postid=15304807#post15304807 target=_blank>Originally posted</a> by bigbus
So that doesn't mean my overflow is draining too fast?



Should I open valve to full and pull water out?



No, it drains what the return pump sends it.

Open it up and remove some water.

[mfinn]

If you feel the water travels through the sump too fast, then you would put a valve on the return or ( best ) get a smaller pump.

[Jocephus]

<a href=showthread.php?s=&postid=15304784#post15304784 target=_blank>Originally posted</a> by mfinn
If the sump overflows, then there is too much water in the system.

I don't think this is 100% correct. If the sump overflows then your overflow pipe is too low.

If your tank is drilled on the back, extend the pipe coming off of the elbow up. If it has durso's (or similar) extend the stand pipe up. that way when the pump cuts off, the water level in the display will not drop low enough to flood the sump.

At least I think that's what you are asking.

[mfinn]

<a href=showthread.php?s=&postid=15304854#post15304854 target=_blank>Originally posted</a> by Jocephus
I don't think this is 100% correct. If the sump overflows then your overflow pipe is too low.

If your tank is drilled on the back, extend the pipe coming off of the elbow up. If it has durso's (or similar) extend the stand pipe up. that way when the pump cuts off, the water level in the display will not drop low enough to flood the sump.

At least I think that's what you are asking.


I was assuming it was a store bought drilled tank.

[bigbus]

No, I have the right amount if water in there right now that if power goes out the sump does not overflow.

But when the power is on, and valve for overflow is fully open, the sump fills up because the return doesn't pump fast enough. This is my guess.

When I first put this together, there was no valve on the overflow. But the sump gathered water faster than what was being pumped out.

So I added a valve on the overflow to regulate it. Now its pretty much constant volume in the sump, but I think its pumping a bit faster than the drain from what I put my overflow valve at.

I don't have an overflow box built or anything, the water from the tank directly drains into the pvc pipe that has a strainer on top.

[Jocephus]

If it does not overflow when the power is out, then why do you need to control the rate when the power is on? Putting a valve on the overflow is a bad idea. The overflow should carrydown to the sump whatever "overflows" the pipe. If your sump fills too fast, raise the pipe with the strainer on it.

[Jocephus]

Okay look at it like this. Turn your pump off. Let the display drain to the top of the pipe with the strainer. Now when you turn your pump back on, how could your tank possibly drain more then what you are pumping into it? Make sense? This is why you use the height of your overflow drain pipe to control the amount of water potentially going to your sump.

[mfinn]

<a href=showthread.php?s=&postid=15304961#post15304961 target=_blank>Originally posted</a> by Jocephus
This is why you use the height of your overflow drain pipe to control the amount of water potentially going to your sump.


+Yes

[bigbus]

I do control the height of the overflow by rotating the pipe to different angles to achieve the lower flow. But at the most optimum spot, it is way too loud so I rotate it a bit more to increase the flow then restrict it with the valve so there is no noise at all.

[mfinn]

By restricting the overflow, you run the risk of overflowing the tank. Eventually the overflow will build up slime and algae and that balnce you have now will go away. Plus and little obstuction, like food or what ever, will change that balance.
I'd look into getting a overflow box around that pipe and then work on lowering the noise level.

[mfinn]

[QUOTE]

oops, triple post:p

[mfinn]

There are a number of places that make them online.

[bigbus]

Even without the valve, the angle that I turn the pipe acts as a restriction only allowing certain flow rates. If I have the drain complete vertical with the opening on top, there is almost no flow to the sump, if I turn it at the 90 degree mark, it has max flow to sump.

[bigbus]

Either way, valve or no valve, I can't get the flows of the drain to match the return

[mfinn]

On my 240 gallon tank, I have two 2" durso stand pipes inside overflow boxes. They can handle several thousand gallons per hour through them. My return pump pumps about 1000 gallons per hour to the tank. To me that is perfectly matched.

When you turn the pipe so that it is straight up, that is the way it is suppose to be.

[bigbus]

I understand what you guys are saying, but my overflow just seems odd.

I just took the valve off, and the overflow is around 500-600 gph 1" pipe.

The pump is going at 400 max due to head loss.

Theoretically the overflow should only be draining at 400 gph right? Even still my sump is filling up faster than the return can pump through.

[jenjen]

Do you have a pic of your setup?

[mfinn]

<a href=showthread.php?s=&postid=15305171#post15305171 target=_blank>Originally posted</a> by bigbus


Theoretically the overflow should only be draining at 400 gph right? Even still my sump is filling up faster than the return can pump through.



Even when the pvc pipe is straight up?

How tall is the pvc pipe?

Does it go up to the top of the tank?

[bigbus]

http://i926.photobucket.com/albums/ad110/lnguyen116/overflow.jpg

photo of the overflow drain

[bigbus]

I mean, I guess it isn't your typical overflow, but I don't really want to change it at the moment.

[jenjen]

Hard to tell what the water level is in the tank - you want the water to be just about level with where it goes into the overflow opening - so in your pic you'd need the water level about the same level as the white portion of the pipe, or raise the closed portion higher toward the surface of the water.

If you have the opening for the overflow below the surface of the water, your tank is just draining as fast as it can. What you want is for it to drain at the rate the pump puts new water into the tank, so it needs to JUST overflow, not have the overflow well below the surface.

[bigbus]

If I rotate it to straight up and down, it pretty much just overflows. But I would have to turn the pump way down less than half to keep water constant in sump.

[cdbias2]

Your overflow can't drain faster than what the return pump puts in.
That's why they call it an overflow.
If the overflow ran faster than the return pump it would be called a drain.
The valve on the return line is a bad idea except for times of maintenance.

[bigbus]

Then would you call that pipe in my tank an overflow or a drain? Probably a drain because it drains faster than my pump can put out.

[jenjen]

I would do this:

* turn the overflow pipe straight up
* turn off the pump
* remove any access water from the sump, so sump is at a comfortable level - mark this level (I use a piece of masking tape and write 'return off')
* put a valve after the pump, so you can throttle back the pump if you need to (note: do NOT use a valve on the drain/overflow)
* turn on the pump

The pump should pump water out of the sump and into the DT, and it should empty out of the DT at the same rate. If it doesn't, the only thing I can think of is the overflow opening is too small and the water level is rising above and then rushing down (ie: creating a vacuum). If it's doing this, turn the valve to slow the rate the return pump is putting water into the DT until it stops.

Once you get it running smoothly, make sure to mark the 'pump on' level in the sump too - these two levels are your top off levels and it helps make sure you reset the system exactly the same next time.

Good luck!

[cdbias2]

If it drained faster, your tank would run dry.
Your just not letting it achive it's "sweetspot" water level.
Or you may be letting it and you are just not happy with it and you are trying to throttle your drain line back.

If it's plumbed properly, the water level in the tank never falls below the overflow and, as long as the return pump isn't too large. the water level will not get above the rim of th tank.

For instance:
You overflow is not draining 500gph if your return pump is only putting in 400gph.
This really isn't that tuff.

[bigbus]

Yea but say my pump is doing 400 gph, my overflow must be doing more than that if the sump is gaining 3 inches or so of water every 10 minutes or so.

[cdbias2]

I can assure you something else is going on. It almost seems like the return pump is getting weaker after a few minutes.

[bigbus]

Like you said, I think mine is more of a drain than an overflow as it sits below the water level. I think I'll stick with the valve, if it ever gets clog there is more than enough room for the pump to run dry before main tank gets flooded.

Theres probably around 4-5 gallons in my return chamber and I have at least 15 gallons of room in the main tank.

[mfinn]

Drain,, overflow,,, both the same.
You should be able to turn the pvc pipe straight up, fill the sump approx. 1/2 way and turn the pump on.

Just curious, what is on the outside of the tank where the pvc pipe goes through?

[mfinn]

<a href=showthread.php?s=&postid=15305364#post15305364 target=_blank>Originally posted</a> by bigbus
If I rotate it to straight up and down, it pretty much just overflows. But I would have to turn the pump way down less than half to keep water constant in sump.


When you say overflows, do you mean the tank overflows?

Plus something else,,, does it seem that the water acts like it flushes down the drain to the sump?

[Jocephus]

<a href=showthread.php?s=&postid=15304997#post15304997 target=_blank>Originally posted</a> by bigbus
I do control the height of the overflow by rotating the pipe to different angles to achieve the lower flow. But at the most optimum spot, it is way too loud so I rotate it a bit more to increase the flow then restrict it with the valve so there is no noise at all.

Okay, here is the root of the problem. "at the most optimum spot, it is way too loud so I rotate it a bit more to increase the flow"

Two different problems. If it is too noisy, get a smaller return pump. That is not a good reason to run as is and risk a flood/fire.

Turn the pipe so that it is straight up, or close to it. Next, put a valve on the outflow side of your return so that you can throttle it back. This will allow you to quiet it down.

[bigbus]

If I turn the pipe so that it is straight up, the sump overflows.

[bigbus]

<a href=showthread.php?s=&postid=15305666#post15305666 target=_blank>Originally posted</a> by mfinn
When you say overflows, do you mean the tank overflows?

Plus something else,,, does it seem that the water acts like it flushes down the drain to the sump?

My mistake.. If I turn the pipe straight up, the return chamber runs out of water.

If I turn the pipe at 90 degrees, the sump overflows.

[bigbus]

<a href=showthread.php?s=&postid=15305764#post15305764 target=_blank>Originally posted</a> by Jocephus
Okay, here is the root of the problem. "at the most optimum spot, it is way too loud so I rotate it a bit more to increase the flow"

Two different problems. If it is too noisy, get a smaller return pump. That is not a good reason to run as is and risk a flood/fire.

Turn the pipe so that it is straight up, or close to it. Next, put a valve on the outflow side of your return so that you can throttle it back. This will allow you to quiet it down.

I'm 99.99% sure that my return is not going too fast. And if I put the pipe straight up my pump will run dry in like 15 seconds.

[cdbias2]

If you turn the pipe straight up that should keep the water in the DT at its highest level which should put the least amount of water in your sump. If your sump overflows, you obviously have too much water in your system.

Turn all of your pumps off and only leave enough water in your sump so that it doesn't overflow. This way you will have some protection during power outages.

[bigbus]

<a href=showthread.php?s=&postid=15305799#post15305799 target=_blank>Originally posted</a> by cdbias2
If you turn the pipe straight up that should keep the water in the DT at its highest level which should put the least amount of water in your sump. If your sump overflows, you obviously have too much water in your system.

Turn all of your pumps off and only leave enough water in your sump so that it doesn't overflow. This way you will have some protection during power outages.

If I turn the pipe straight up, the return chamber runs dry. The water drops below pump and is only like 1" so water wont pump back up.

Are you saying put pipe straight up and add more water?

[mfinn]

<a href=showthread.php?s=&postid=15305797#post15305797 target=_blank>Originally posted</a> by bigbus
I'm 99.99% sure that my return is not going too fast. And if I put the pipe straight up my pump will run dry in like 15 seconds.



If the sump runs dry,,, add more water.

[Jocephus]

<a href=showthread.php?s=&postid=15305807#post15305807 target=_blank>Originally posted</a> by bigbus
Are you saying put pipe straight up and add more water?

Yes

[Jocephus]

<a href=showthread.php?s=&postid=15305809#post15305809 target=_blank>Originally posted</a> by mfinn
If the sump runs dry,,, add more water.

+1

I think this will do it for you. If it is too loud, consider turning your pump down a bit with a valve.

[cdbias2]

Add more water?
He says his sump already overflows!

[Jocephus]

He says his sump overflows with his outlet pipe completely below the surface of the water. That will happen. By turning it straight up, he increases the level of water in his display (thereby reducing the level in his sump), and even if his return pump failed (blackout etc...) the water would only drop to the height of the pipe opening. So yes, add more water. But only after you turn the pipe vertically (12 o'clock).

[mfinn]

<a href=showthread.php?s=&postid=15305845#post15305845 target=_blank>Originally posted</a> by cdbias2
Add more water?
He says his sump already overflows!


He also said it runs dry when the overflow pipe is in the correct up position.

[bigbus]

I will try to put the pipe up 12 o'clock and I will add more water to return chamber and see what happens.

[jdieck]

Here is what I would try:
1. Turn the drain/overflow elbow so it is pointing up (Were you say the pump runs dry)
2. Fully open both valves, the pump return and the drain valve if you still have one.
3. Add water to the main tank and keep adding it until it drains to the sump. Keep adding water to the main until the sump level fills about 80% of the sump.
4. Turn on the pump, the water level in the main will rise and the level in the sump drop but not enough to overflow the main nor to empty the sump. If the sump runs dry or the main seems to overflow close the return valve until the level in the main tank stops rising and the sump level stops dropping.

[bigbus]

At the 12 o'clock, it does run dry but I will add more di water, and It is loud as hell. Gurgles like no other, I don't think slowing down the return will help.

[mfinn]

Once you get the first problem solved, then there are ways to solve the gurgling, or atleast quiet it down to a acceptable level.

[Jocephus]

<a href=showthread.php?s=&postid=15305911#post15305911 target=_blank>Originally posted</a> by mfinn
Once you get the first problem solved, then there are ways to solve the gurgling, or atleast quiet it down to a acceptable level.

+1

[bigbus]

Well, the gurgling was way too loud, I put it back to what it was at before. The levels are balanced and if pump shuts off the sump has at least 2" left after overflow.

[mfinn]

bigbus
I used a upturned pvc 90 in a couple tanks in the past. I agree the gurggling can be annoying, but the use of a valve on a single sump line can be a hobby killer, after a couple water spills on a hardwood or new carpet floor.

On one tank that had two 2inch pvc 90's, I used a small rolled up piece of gutter guard stuffed down into the 90 which acted as a channel for the water to flow down, which made it a little quieter.
On another I used a pvc reducer with the large end facing up. This gave the water a wider channel to flow into, which made a difference in the noise.

One thing that these tanks had in common were, they both had a pvc tee on the outside of the tank. Kind of like a modified durso.
This will also help quiet things down.



HTH

[jdieck]

Another alternative is to turn the elbow so it is pointing directly down and drill a 1/8" hole on the top of the pipe or elbow. This way the water will drain by gravity rather than syphon.

[EnglishRebel]

I'm confused here. All I've ever read and my own experience with my Dursos is that the returns will only flow as much as you pump into the tank unless you are pulling a full syphon with some other sort of return piping configuration. Change to a proper Durso and you will have no problems.

[billdogg]

I belive englishrebel has hit the nail on the head! A standard 1" drain will handle about 300 - 350 gph safely (without siphon) At full siphon, which is what seems to be happening here, you increase that flow to 600gph or so, but there is NO margin for error. Any obstruction whatsoever will result in a flood, as the tank overflows, and a (probably) burnt up return pump as it runs dry.

If a proper durso (as suggested) or stockman or any variation thereof is used, the problem corrects itself. The excessive noise is a result of too much flow - a simple gate or ball valve on the OUTPUT side of the pump will allow you to tone down the flow to reduce or elliminate the noise. Restricting the drain from the tank in any manner is just a flood that has not happened yet.

[evsalty]

Make it look like this and your problems should be solved like said above.

http://www.4everb.com/drain_inlet.jpg