Removing Micro Bubbles

[ShadowStryder]

I have a Mag 24 which has a 1" return plumbing at 6' head. My question is the return produces tons of micro
bubbles coming back into tank. I am assuming it has something to do with the impellor in the pump. Is there
a way to stop it and or what exactly causes it.

Here is a pic to show what it looks like. It appears as if the water is cloudy from a distance but in actuality it
is millions of bubbles. Any help would be appreciated.

 

[z400]

Sounds like you have an airleak somewhere in your system.

 

[Source310]

just reseal all the piping from only the inlets. there is gaps in the piping or hose which is causing the filter to suck in air.

 

[ShadowStryder]

This is a 3 chamber open system DIY sump. I also have air stones under 2 chambers of Bio Media. But the Micro bubbles are not from that. There are no bubbles in the pump chamber of the sump. So they have to be created within the pump or the return plumming. But I would think if in the return plumming it would leak from the pressure of the pump, wouldn't it? Could there be so much pressure and agitation with the impeller and return that could create the bubbles from the existing water itself?

Thanks for the responses.

 

[skjl47]

This is a 3 chamber open system DIY sump. I also have air stones under 2 chambers of Bio Media. But the Micro bubbles are not from that. There are no bubbles in the pump chamber of the sump. So they have to be created within the pump or the return plumming. But I would think if in the return plumming it would leak from the pressure of the pump, wouldn't it? Could there be so much pressure and agitation with the impeller and return that could create the bubbles from the existing water itself?

Thanks for the responses.

Hello; I believe that what you describe is called cavitation. I also seem to recall that with cavitation the gases that are dissolved in the water do errupt as small bubbles from the drastic pressure changes induced by an impeller. Is it possible to vary the speed the RPM's of the impeller?

One other thought has to do with the position of the impeller in relation to the source of water that it pumps. Is it close enough to the surface of the water to create a vortex and suck air into itself?

 

[ShadowStryder]

Hello; I believe that what you describe is called cavitation. I also seem to recall that with cavitation the gases that are dissolved in the water do errupt as small bubbles from the drastic pressure changes induced by an impeller. Is it possible to vary the speed the RPM's of the impeller?

One other thought has to do with the position of the impeller in relation to the source of water that it pumps. Is it close enough to the surface of the water to create a vortex and suck air into itself?

I believe Cavitation is what I have going on. No I can't vary the speed of the impeller and it isn't close to the surface. It is appx 20" below surface..

Thanks for your reply,

 

[Chris-Chicago]

You may have too much back pressure. What size pipe does the pump manufacture recommend. If you are using 1" return piping, and pump manufacture says 1.5" or 2" you have seriously restricted the flow. Can you experiment by temporarily using 1.5 or 2" flexible hose from the pump back in to the tank and try running that way for a while? An hour, 2 hours, 4 hours to see what happens? Assuming when you turn off the filter and let water settle in a short while all the microbubles float up and the water becomes very clear? If so you need to some plumbing

 

[ShadowStryder]

Manufacturer recommends 1" plumbing which is what I use. I have a check valve throttled down maybe 10% but added a T with 1" plumbing before the check valve plumbed back to the sump running wide open to allow for any back pressure. So I don't believe back pressure is the issue, but then I am far from an expert in this area.

 

[shelferich]

A 1 inch return line should be fine for a mag 24. Is it a hard line or flexible tubing? Assuming the pump is not sucking air then it has to be coming from a small leak in the return line I would think. Maybe a syphon break hole is allowing air in?

 

[ShadowStryder]

A 1 inch return line should be fine for a mag 24. Is it a hard line or flexible tubing? Assuming the pump is not sucking air then it has to be coming from a small leak in the return line I would think. Maybe a syphon break hole is allowing air in?

I do have a syphon break hole drilled below the surface area, but have never heard it sucking air into it. Hard line for the plumbing. Will shut the pump off tomorrow and reseal some of the connections to see if it is sucking air in that way. I just figured given the pressure that it would have leaked out of any possible bad seals.