Micro bubbles from return pump?

[swilliams2207]

I’ve been troubleshooting micro bubbles in my display for a month now. Tank was set up mid November so still new, but thinking I should be well beyond the micro bubble stage. It’s not a crazy amount of bubbles and it has died down a bit, however it’s still noticeable enough to make the water look hazy.

Tank is 150 cube with 40 breeder sump with single return baffle. Have a bubble trap sponge in the return chamber to eliminate bubbles reaching my return pump. I run a Reefmat. Not currently running a skimmer. Running a vectra l3 at about 30%. When I ramp the pump up more, the bubbles get worse.

I do have exposed 1 inch jumbo loc line on the return that extends out of the water. This is my only idea for how air could be getting in the tubing however it seems like a standard return design?

Pump is submerged fully and no vortex. No micro bubbles appear to be in the return chamber.

Here are pics of loc line and return.

Should I hard plumb the return tubing below the water line before adding the loc line? Any other troubleshooting ideas?

 

[Cichlid Dad]

Full shot of your sump will be needed. Looks like a diy setup from the picture

 

[Garf]

I’ve been troubleshooting micro bubbles in my display for a month now. Tank was set up mid November so still new, but thinking I should be well beyond the micro bubble stage. It’s not a crazy amount of bubbles and it has died down a bit, however it’s still noticeable enough to make the water look hazy.

Tank is 150 cube with 40 breeder sump with single return baffle. Have a bubble trap sponge in the return chamber to eliminate bubbles reaching my return pump. I run a Reefmat. Not currently running a skimmer. Running a vectra l3 at about 30%. When I ramp the pump up more, the bubbles get worse.

I do have exposed 1 inch jumbo loc line on the return that extends out of the water. This is my only idea for how air could be getting in the tubing however it seems like a standard return design?

Pump is submerged fully and no vortex. No micro bubbles appear to be in the return chamber.

Here are pics of loc line and return.

Should I hard plumb the return tubing below the water line before adding the loc line? Any other troubleshooting ideas?

You got an anti Syphon hole in the loc line?

 

[TokenReefer]

Not saying this is the issue but is the return coming up from inside the overflow? What is the second pump?

 

[swilliams2207]

You got an anti Syphon hole in the loc line?

I do not no. I know it’s not air tight however.

 

[Garf]

I do not no. I know it’s not air tight however.

It may be sufficiently airtight to Syphon your tank though. Have you tried turning the return pump off, see if it overflows your sump? Either way, the water level above your return pump looks quite low to me. You could always see if increasing the level in the sump stops it bubbling up.

Edit, I'd stick a hole in the loc line

 

[swilliams2207]

It may be sufficiently airtight to Syphon your tank though. Have you tried turning the return pump off, see if it overflows your sump? Either way, the water level above your return pump looks quite low to me. You could always see if increasing the level in the sump stops it bubbling up.

Edit, I'd stick a hole in the loc line

I’ll

It may be sufficiently airtight to Syphon your tank though. Have you tried turning the return pump off, see if it overflows your sump? Either way, the water level above your return pump looks quite low to me. You could always see if increasing the level in the sump stops it bubbling up.

Edit, I'd stick a hole in the loc line

it will siphon but I positioned everything so the sump can handle the drainage when powered offf. I can try raising water level but how would that help if the pump is already fully submerged?

 

[Idoc]

It sounds like you have a small leak in the piping leading to the display tank that is sucking in air. It is more than likely at a connection of two pipes/fittings somewhere in that line.

 

[Dom]

I do not no. I know it’s not air tight however.

Yes, you may be drawing in air somewhere along the return.

Is your protein skimmer close by? I had a micro bubble issue from my return picking up stray bubbles from the skimmer.

 

[swilliams2207]

Added more sump shots. Skimmer has been off for weeks so not from that.

 

[John K]

It sounds like you have a small leak in the piping leading to the display tank that is sucking in air. It is more than likely at a connection of two pipes/fittings somewhere in that line.

On the output side? Under pressure? Other than a venturi effect at the output/locline I don't see how the output would suck air in instead of push water out?

My two diagnostic ideas are;
1- (as already suggested) try increasing the water level in the sump (temporarily) to see if the return pump being deeper stops the bubbles.

2- Actually lower that loc line a little deeper in the display water (temporarily) to see if you are getting a venturi effect at the output (being submerged, the venturi effect would suck in water but not air). {Then lower it again, and definitely add that siphon break hole}

 

[swilliams2207]

On the output side? Under pressure? Other than a venturi effect at the output/locline I don't see how the output would suck air in instead of push water out?

My two diagnostic ideas are;
1- (as already suggested) try increasing the water level in the sump (temporarily) to see if the return pump being deeper stops the bubbles.

2- Actually lower that loc line a little deeper in the display water (temporarily) to see if you are getting a venturi effect at the output (being submerged, the venturi effect would suck in water but not air). {Then lower it again, and definitely add that siphon break hole}

I can't lower the loc-line since it moves up and over the overflow box. Some portion will always be above water as configured. It's as low as I can get it. Is a siphon break hole necessary if the sump can handle the set amount of backflow in power outage? I can shut down my entire system and the siphon breaks on its own after the drain level falls below the return nozzle. This won't overflow my sump.

 

[Idoc]

On the output side? Under pressure? Other than a venturi effect at the output/locline I don't see how the output would suck air in instead of push water out?

My two diagnostic ideas are;
1- (as already suggested) try increasing the water level in the sump (temporarily) to see if the return pump being deeper stops the bubbles.

2- Actually lower that loc line a little deeper in the display water (temporarily) to see if you are getting a venturi effect at the output (being submerged, the venturi effect would suck in water but not air). {Then lower it again, and definitely add that siphon break hole}

A small air leak at a connection will definitely suck in air as the water is pushed/rushed upward through the pipes to the display tank creating small bubbles. Sometimes you will see small amounts of water around the connection, but it may only be very slight.

Taking tape and putting around each connection very tightly in succession will help diagnose which connection is causing the problem.

Another place to look would be in the sump itself. If small air bubbles from the skimmer or something else are making their way to the return pump, it will also create small air bubbles in the display tank as they are pushed upward from the sump.

 

[swilliams2207]

Not saying this is the issue but is the return coming up from inside the overflow? What is the second pump?

Yes it is. Glass cages build. Duel returns for UV.

 

[swilliams2207]

A small air leak at a connection will definitely suck in air as the water is pushed/rushed upward through the pipes to the display tank creating small bubbles. Sometimes you will see small amounts of water around the connection, but it may only be very slight.

Taking tape and putting around each connection very tightly in succession will help diagnose which connection is causing the problem.

Another place to look would be in the sump itself. If small air bubbles from the skimmer or something else are making their way to the return pump, it will also create small air bubbles in the display tank as they are pushed upward from the sump.

Not to sound like a jerk but how can air be sucked in through my pvc connections without water escaping? I don’t have any leaks and I took good care to prime and glue my connections.

 

[swilliams2207]

I added more water to the return section and to doesn’t seem to be helping. I feel like it has to be the loc line? Or could it be the pump itself? Should I try a different pump to see if that helps?

 

[fishyjoes]

If you think it's the loc line but aren't sure you could temporarily replace it with a piece of flexible tubing just as a test.
You could do the same thing all the way back to the return - temporarily change the plumbing to a single flexible hose that just hooks over the side - run it like that for an hour or whatever and see how that goes.
This way you can narrow down the source of the bubbles using a device that is known not to introduce any.

 

[BetterJake]

I have had issues with micro bubbles in my tank when my skimmer was breaking in or if my skimmer was having trouble with removing something from the system.

So.. If you leave everything running and just shut off the skimmer, does it stop?

 

[swilliams2207]

I have had issues with micro bubbles in my tank when my skimmer was breaking in or if my skimmer was having trouble with removing something from the system.

So.. If you leave everything running and just shut off the skimmer, does it stop?

Skimmer has been off for a month. It improves slightly with skimmer off but still minor bubbles.

 

[swilliams2207]

If you think it's the loc line but aren't sure you could temporarily replace it with a piece of flexible tubing just as a test.
You could do the same thing all the way back to the return - temporarily change the plumbing to a single flexible hose that just hooks over the side - run it like that for an hour or whatever and see how that goes.
This way you can narrow down the source of the bubbles using a device that is known not to introduce any.

Yeah I think this is my only option at this point. I’ll bite the bullet and run some experiments.