Overflow Issues
- Thread starter Anthrax15
- Start date
How big is the tank? With the drain setup you are running you will not get a high volume of water through the sump, and there is no real advantage to having a high volume of water trough the sump. A pic of the whole sump will help figure out the easiest solution.
dkeller_nc
New member
This is hard to discern from your pictures, but your overflow standpipe should have a small hole drilled in the top of it. The function that hole is to allow air into the standpipe to prevent the waterflow going through it from "grabbing" a lot of air and forcing it down into your sump (the technical term for this is entrainment).
One other thing that I can't tell from your picture is whether your overflow has an emergency drain or not. Most modern drain setups have 3 holes drilled through the bottom of the overflow - one is for the normal overflow standpipe, one is for plumbing the return up through the overflow (and thus hiding it), and the 3rd hole is for an emergency drain in case the primary gets plugged with a snail or algae.
If, and only if, your overflow has an emergency standpipe, you can install a ball valve on the primary tank drain. What this allows you to do is restrict the drain so that water backs up a few inches into the drain pipe, which greatly cuts down on entrainment of air. However, doing this without an emergency overflow is really risky, because the partially closed ball valve can easily clog with something and overflow your main tank.
If you don't have an emergency drain, here's another solution to reduce microbubble entrainment in the drain flow: buy a piece of 4" or 6" PVC pipe and a piece of scrap acrylic or glass that is sufficient to block up one end of the pipe. Glue this piece of acrylic or glass onto the end, and install it in your sump so that the primary tank drain empties at least 6" down into it. The water will flow up the interior of this piece of PVC, and cascade down the outside to form a film of flowing water. Essentially what you're doing is installing another baffle in your sump, just that it's round.
One other thing that I can't tell from your picture is whether your overflow has an emergency drain or not. Most modern drain setups have 3 holes drilled through the bottom of the overflow - one is for the normal overflow standpipe, one is for plumbing the return up through the overflow (and thus hiding it), and the 3rd hole is for an emergency drain in case the primary gets plugged with a snail or algae.
If, and only if, your overflow has an emergency standpipe, you can install a ball valve on the primary tank drain. What this allows you to do is restrict the drain so that water backs up a few inches into the drain pipe, which greatly cuts down on entrainment of air. However, doing this without an emergency overflow is really risky, because the partially closed ball valve can easily clog with something and overflow your main tank.
If you don't have an emergency drain, here's another solution to reduce microbubble entrainment in the drain flow: buy a piece of 4" or 6" PVC pipe and a piece of scrap acrylic or glass that is sufficient to block up one end of the pipe. Glue this piece of acrylic or glass onto the end, and install it in your sump so that the primary tank drain empties at least 6" down into it. The water will flow up the interior of this piece of PVC, and cascade down the outside to form a film of flowing water. Essentially what you're doing is installing another baffle in your sump, just that it's round.
Anthrax15
New member
The tank is a 60g cube with a 20g High sump. No emergency drain installed just the overflow and return.
I do like the idea you had dkeller. Basically its a filter sock that just is constantly overflowing?
The inlet pipe is very rigid and I can't think of a way that I could show it down at a 90 degree angle.
<a href="http://www.flickr.com/photos/anthrax15/9659013322/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2849/9659013322_2d7247765b.jpg" width="500" height="375" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9659014840/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm6.staticflickr.com/5493/9659014840_02f4ed1e66.jpg" width="375" height="500" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9659019380/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm8.staticflickr.com/7288/9659019380_aa46d3894b.jpg" width="500" height="375" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9655787289/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2848/9655787289_c89f6abefe.jpg" width="375" height="500" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9639164920/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm4.staticflickr.com/3667/9639164920_a17c00053e.jpg" width="500" height="375" alt="Untitled"></a>
I do like the idea you had dkeller. Basically its a filter sock that just is constantly overflowing?
The inlet pipe is very rigid and I can't think of a way that I could show it down at a 90 degree angle.
<a href="http://www.flickr.com/photos/anthrax15/9659013322/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2849/9659013322_2d7247765b.jpg" width="500" height="375" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9659014840/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm6.staticflickr.com/5493/9659014840_02f4ed1e66.jpg" width="375" height="500" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9659019380/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm8.staticflickr.com/7288/9659019380_aa46d3894b.jpg" width="500" height="375" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9655787289/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2848/9655787289_c89f6abefe.jpg" width="375" height="500" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9639164920/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm4.staticflickr.com/3667/9639164920_a17c00053e.jpg" width="500" height="375" alt="Untitled"></a>
dkeller_nc
New member
Based on your pictures you don't have the option of installing a ball valve on the overflow outlet to the sump, as you have no emergency standpipe. However, you can still install a PVC overflow baffle as described earlier. Yes, if you want to look at it that way, the construction I described could be visualized as a constantly overflowing filter sock.
dkeller_nc
New member
The PVC for the bubble baffle is going to need to be at least 4-6" in diameter. You want the slowest, thinnest film of water overflowing completely around the perimeter that you can get. BTW - It may be necessary to have this PVC professionally cut, or at least cut on a miter saw, because it must be absolutely straight up and down when mounted in your sump. Otherwise, the flow will be only on one side instead of the whole perimeter, which will greatly reduce its effectiveness.
The reinforced flex tubing that you have probably can't be bent to go in such a device. You will either have to hard-plumb the drain, or turn the sump completely around in the stand so that it enters the correct chamber without having to be forced over a baffle as in your picture.
Anthrax15
New member
Alright so here is what I have so far. I was able to find an attachment and make a 90 degree bend so the tubing would go in the PVC bubble baffle. The PVC diameter is 4". Im just waiting for the silicon to dry for the bubble baffle and I will test it out.
Anything I need to fix or change? I will be running a piece of PVC down the inlet tubing so it goes to the bottom of the bubble baffle. How high does the bubble baffle need to be with the water level? Above, at, or below the water level?
Inlet:
<a href="http://www.flickr.com/photos/anthrax15/9681091557/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm6.staticflickr.com/5515/9681091557_2b92fc3caf.jpg" width="375" height="500" alt="Untitled"></a>
Bubble baffle before I cut it down:
<a href="http://www.flickr.com/photos/anthrax15/9681090285/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2892/9681090285_f741cf5c13.jpg" width="375" height="500" alt="Untitled"></a>
Anything I need to fix or change? I will be running a piece of PVC down the inlet tubing so it goes to the bottom of the bubble baffle. How high does the bubble baffle need to be with the water level? Above, at, or below the water level?
Inlet:
<a href="http://www.flickr.com/photos/anthrax15/9681091557/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm6.staticflickr.com/5515/9681091557_2b92fc3caf.jpg" width="375" height="500" alt="Untitled"></a>
Bubble baffle before I cut it down:
<a href="http://www.flickr.com/photos/anthrax15/9681090285/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2892/9681090285_f741cf5c13.jpg" width="375" height="500" alt="Untitled"></a>
dkeller_nc
New member
It needs to be well above the water level. What you're trying to do is to get a thin film of water to overflow the PVC tube baffle. That film will contain bubbles, which will break as they travel down that thin film of water.
Essentially, what you're doing is the same thing as a triple-baffle setup in a traditional sump. One advantage to the PVC pipe baffle design is that it can be moved around the sump and/or removed if necessary.
Essentially, what you're doing is the same thing as a triple-baffle setup in a traditional sump. One advantage to the PVC pipe baffle design is that it can be moved around the sump and/or removed if necessary.
Anthrax15
New member
So I installed the bubble baffle and we are still getting microbubbles in the DT. It's driving me crazy!
<a href="http://www.flickr.com/photos/anthrax15/9687453149/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm4.staticflickr.com/3791/9687453149_229673db39.jpg" width="375" height="500" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9687453857/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm6.staticflickr.com/5473/9687453857_6be474ffc0.jpg" width="375" height="500" alt="Untitled"></a>
Microbubbles in DT:
<a href="http://www.flickr.com/photos/anthrax15/9687454537/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2891/9687454537_141edfb872.jpg" width="500" height="375" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9687453149/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm4.staticflickr.com/3791/9687453149_229673db39.jpg" width="375" height="500" alt="Untitled"></a>
<a href="http://www.flickr.com/photos/anthrax15/9687453857/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm6.staticflickr.com/5473/9687453857_6be474ffc0.jpg" width="375" height="500" alt="Untitled"></a>
Microbubbles in DT:
<a href="http://www.flickr.com/photos/anthrax15/9687454537/" title="Untitled by Anthrax15, on Flickr"><img src="http://farm3.staticflickr.com/2891/9687454537_141edfb872.jpg" width="500" height="375" alt="Untitled"></a>
dkeller_nc
New member
You may not be able to completely eliminate the micro-bubbles, but you should be able to get close.
A couple of other suggestions:
Drill about a 1/8" hole in the top of the elbow of your fitting that goes into the bubble baffle. That should allow some of the entrained air in the drain to escape before it gets flushed into the baffle, mixed with air and creates lots of little bubbles. The upper part of the drain fitting in the overflow should also have a small hole in it - this is the essence of the Durso drain design.
Make sure that you're working on the piece of equipment that's causing you the grief - skimmers are known for putting out micro-bubbles, and they can usually be fixed by adding a foam sleeve to the output of the skimmer.
Also, realize that if the only thing you've got in the tank at this point is saltwater, you're going to have way more bubbles than when you've added live rock and sand. It's counter-intuitive, because the LR and critters produce the waste that creates the foam in the skimmer, but I can tell you first hand that there's a big difference between a saltwater-only tank (particularly new saltwater) and one that's been stocked.
Buy a ball valve (or better, a gate valve) and put it on the output of your return pump. How much air you entrain going over the overflow and into the drain sensitively depends on the flowrate. You may be able to dial back the flowrate by 20% and make a huge difference with the bubble baffle (that's what Sirreal was suggesting).
There's really no reason to have a large amount of flow going through your sump with modern set-ups and propeller pumps inside the tank. You really only need 3-5 times the system volume going through the sump per hour.
Finally, if you've taken the above steps and still cannot dial it in the way you want, you're going to have to install a triple-baffle in your sump. While more involved than the PVC pipe bubble baffle, it's still not all that hard. The drawback to doing it, though, is that you must remove the sump, empty it, dry it completely, clean the inside glass where you're going to install the triple baffle with acetone to ensure a good glue bond, use aquarium-safe silicone, and allow it to cure for a minimum of 24 hours.
If you go this last route, you've a choice - you can make the triple baffle out of glass, or acrylic, or both. Cutting acrylic is easy, glass, not so much. If you want to go with glass, you can usually get a glass-specialty shop to cut the pieces you require out of scrap. It may be even less expensive to go to a full-service hardware store like Ace and get them to cut window glass to your specifications. For acrylic, most cities have an acrylic & fiberglass specialty supply house. Many of these stores sell their off-cuts for cheap to students in the design school at a local University.
A couple of other suggestions:
Drill about a 1/8" hole in the top of the elbow of your fitting that goes into the bubble baffle. That should allow some of the entrained air in the drain to escape before it gets flushed into the baffle, mixed with air and creates lots of little bubbles. The upper part of the drain fitting in the overflow should also have a small hole in it - this is the essence of the Durso drain design.
Make sure that you're working on the piece of equipment that's causing you the grief - skimmers are known for putting out micro-bubbles, and they can usually be fixed by adding a foam sleeve to the output of the skimmer.
Also, realize that if the only thing you've got in the tank at this point is saltwater, you're going to have way more bubbles than when you've added live rock and sand. It's counter-intuitive, because the LR and critters produce the waste that creates the foam in the skimmer, but I can tell you first hand that there's a big difference between a saltwater-only tank (particularly new saltwater) and one that's been stocked.
Buy a ball valve (or better, a gate valve) and put it on the output of your return pump. How much air you entrain going over the overflow and into the drain sensitively depends on the flowrate. You may be able to dial back the flowrate by 20% and make a huge difference with the bubble baffle (that's what Sirreal was suggesting).
There's really no reason to have a large amount of flow going through your sump with modern set-ups and propeller pumps inside the tank. You really only need 3-5 times the system volume going through the sump per hour.
Finally, if you've taken the above steps and still cannot dial it in the way you want, you're going to have to install a triple-baffle in your sump. While more involved than the PVC pipe bubble baffle, it's still not all that hard. The drawback to doing it, though, is that you must remove the sump, empty it, dry it completely, clean the inside glass where you're going to install the triple baffle with acetone to ensure a good glue bond, use aquarium-safe silicone, and allow it to cure for a minimum of 24 hours.
If you go this last route, you've a choice - you can make the triple baffle out of glass, or acrylic, or both. Cutting acrylic is easy, glass, not so much. If you want to go with glass, you can usually get a glass-specialty shop to cut the pieces you require out of scrap. It may be even less expensive to go to a full-service hardware store like Ace and get them to cut window glass to your specifications. For acrylic, most cities have an acrylic & fiberglass specialty supply house. Many of these stores sell their off-cuts for cheap to students in the design school at a local University.
dkeller_nc
New member
Glad you got it fixed. Bubble elimination can be pretty aggravating.
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