Overflow Problems

[cindre2000]

My tank has been drilled to fit 3/4" tubing and I set up a simple pvc elbow and a piece of pvc tubing to provide an overflow. The top tank drains to the bottom tank, which drain to the sump.

My problem is that I have a quiet one pump that when running a maximum head, creates this really really loud gurgiling. Also, the water surges every 10 seconds and splashed all over the place, getting everything wet.

Since I built the tank, I have just lowered the flow so that air no longer gets sucked in and there is no surging. However, I want more flow in my tank. Right now, the I am getting only a tiny bit of flow through my tanks. I would prefer a turn over to match my protein skimmer (350 gph).

Do you guys have any suggestions on how to fix this problem?

 

[Anonymous]

Sounds like you have a standpipe stepup, correct? You need to modify the overflow tube to stop the gurgling. Check out Durso pipe or variation of it. This should help considerably.

 

[cindre2000]

I have considered the durso, however that will stop the surface skimming. Actually I have an idea of what I can do, I will go to lowes and see if it will work and post my results. Thank you for getting the wheels in my head turning.

 

[Anonymous]

For small tank, it is difficult to have a surface skim box due to size constrains. You maybe able to combine a surface skim box with durso standpipe in a small package, but I have no useful idea as to how to get that done. Any nano people that get such gadget?

 

[Anonymous]

It kind of sounds like this situation

When you increase the flow to what you want it gurgles and then surges. That is due to the water pressure above the overflow increasing to the point where a full siphon is created. At that point a lot more water will drain out very quickly until a bit of air is introduced, then the siphon will stop and it will go back to just draining noisily. That will repeat over and over.

Putting a durso in there would fix that, but you would not be surface skimming like you said.

You need to either add more drain area, ie, another bulkhead fitting so you can max out the drains without creating a full siphon, or you need to figure a way to quiet it and keep it from creating a full siphon while you are running it at max flow.


Here are a couple things to try, not sure if either of them will actually solve it.

1. Stick a 90 degree elbow on top of your overflow. That will make it so the drain hole is vertical instead of horizontal, and then the water will have to raise all the way to the top of it to create the full siphon. This one might actually make it noisier, although its worth a try.

2. take some airline tubing and while its running at full flow, stick the tubing down the drain. Only use a short piece. This will allow the drain to suck air through the tube and it won't be able to establish a full siphon. Be careful while you are doing this and watch the top tank water level, if there is no way the drain can handle the flow without a full siphon the tank will overflow while you do this.


Hope that helps, its all I could think of this early in the morning

Personally I would build an overflow box around the drain and put a durso in there.

 

[cindre2000]

That sounds exactly like my situation.

I did try the airline tubing trick.

However there is a slight problem due to my drainage tubing, the tube actually dips down and creates a standing area of water that then fills up to the highest point and then flows down again. However, when the air gets sucked in, all of this water tends to rush into the tank periodically, causing a lot of spray.

I am not sure about the idea of the tank siphoning. The return line is only 1/2 inch while the stand pipe is 3/4. I do not the elbow will help since the siphon would run faster than the return.

I have not been able to get to Lowes yet so I cannot try the other solutions; however, I want to try as hard as possible to not add another drainpipe. I have little enough space as it is.

What I was thinking, was to make a stockman setup. However, the stockman would be placed inside a very small overflow box. However, fine tuning such a set up would be a pain; especially since the tank is already stocked. I guess I might have to pull out my buckets and put all my rock and coral in there while i work on this.

Thanks for the help so far.

 

[Anonymous]

I normally have trouble stating my thoughts exactly and clearly enough for people to understand, even though they make sense in my head

The tank siphoning would be a bad thing, I guess I should of used the words "True Siphon" That would be where there is all water, and no air going down the tube. That causes the water in the drain to pull the rest down faster. Its very hard to get a system that works correctly with an actual true siphon in the mix.


The elbow idea I wrote goes like this. If you put an elbow on top of the drain pipe that is in the picture, then the water will run in the elbow from the side. That way the entire surface of the drain is not under the surface of the water. Doing this will prevent you from drawing a "true siphon"



The drain tubing going uphill and then downhill could be causing some of your problems too. If you can make that so its all downhill or horizontal while its in the tube you will be better off.


Maybe that clarified my thoughts a bit.