Skimmer box problem with drain on new tank. Need help!

[bodie]

I just set up my 50 gallon Seaclear tank with built in skimmer box. I am using a MegaFlow Sump Filter that I purchased from DrsFosterSmith.com. http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=13648&N=2004+22778
The filter came with a plastic flexible drain hose, but I ended up using the clear tubing that came with my Seaclear tank to drain from the skimmer box to the filter. The problem is when the water drains from the skimmer box it drains normally for a couple of seconds and then you can see a big air bubble force it's way down the tube and into the filter. When the big air bubble gets down into the filter, it unleashes a surge of water through the filter. The surge of water is similar to what you would see in a jacuzzi. There is a cover on top of the filter that is supposed to prevent evaporation, but the surge of water is so strong that it blows water everywhere and is very loud. It hasn't been a problem so far except for the noise, but I know this isn't the proper way for the filter to drain. I don't know why I have a huge air bubble force it's way down every couple of seconds and I'm concerned that the water will eventually overflow out of the filter. The tank appears to be filled to proper water level, but the tube that drains the water from the skimmer box to the filter isn't completely filled with water. It drains quietly when it isn't completely filled with water, but when the amount of water increases, which happens every couple of seconds, it forces that big air bubble through which causes the surge. I can't figure out if the problem is with the tube, the water level, the skimmer box or some other issue. Can anyone offer any suggestions as to what is wrong and how it can be resolved? If it would only drain consistently, I think the problem would be resolved, but it currently drains with a certain amount of water pressure and then pushes more water down every couple of seconds.

 

[dscount]

Have you looked into putting a ball valve on the INPUT from the tank into the sump? You can control the flow or "limit" the amount going into the sump box. Your other option is what is the capacity of the return pump?

Is the line from the tank to the sump a straight DROP, have loops or do you have an angled path? (This setup can help aleve the problem a little bit.)

Your "Next" problem will most likely be the sound of a flushing toilet from the skimmer box.

 

[bodie]

I don't have a ball valve on the input, but there is a ball valve on the output line to return the water to the tank. I'm running a Mag Drive pump that runs at 700 gph. I'm not sure, but I don't think I can adjust the amount of return flow on the Mag Drive. I didn't notice anything to adjust the gph.

The line from the tank to the sump is not a straight drop, it's more like a half of a U shape. The bulk head fitting curves, so there's no way that the line can be a straight drop. I've tried adjusting every thing I can think of, but I can't get rid of that air pocket that keeps forcing it's way down every 3 seconds. This noise is driving me crazy! I'm not going to be able to keep this up much longer. I'm getting the impression that I'm going to have to disassemble the set up. I was really hoping to avoid this because it was really difficult to get that line connected and I'm not sure if I can remove the line now that it's attached. Does anyone know how I can get rid of this air pocket that keeps forcing it's way down?

 

[Guest]

My suggestion would be to use what came with the setup. The Plastic hose has ridges inside that will aid in the flow and quiet down the noise. It sounds to me as though you do not have a large enough discharge hose and it is gasping (if you will) for air. This is the cause of the air bubble... Replace the hose and see if that helps.

 

[bodie]

I also thought that might be the problem, but I don't think I can install the plastic hose with ridges to the tank. The bulk head fitting on the bottom of my skimmer box has grooves on it and the plastic hose isn't adjustable and will not wrap around the bulk head fitting securely. I suppose I could take some plastic PVC tubing that I'm currently using to connect the skimmer box to the filter and place it in between the plastic hose with ridges and the bulk head. I've been trying to think of a way to just draw out the air pocket, but so far I haven't thought of anything that would work. Also, I don't know if drawing the air pocket out would permanently resolve the problem or if it would only temporarily relieve the problem. If the air pocket is caused by the length of the discharge tube, then it obviously wouldn't resolve the problem. When you say I "don't have a large enough discharge hose" are you referring to the length of the hose or the inner diameter of the tube? Do you think if the hose was longer it would get rid of the air pocket?