Very small air bubbles coming out of return?

[mlovelace]

Hello, I was curious if there should be very small air bubbles coming out of the return (from Sump). I have noticed the higher I keep the water in my sump/aquarium, there are no bubbles. The lower the sump is with water, the more bubbles I get in the return. I just changed the hose coming from my pump to the return, could this have caused some air pockets? I wouldn't think so or could there be a build up inside the return causing bubbles? When I first received and ran the tank (during cleaning), I noticed an uneven flow coming out, so I took a plastic wire and cleaned it out. I found an old snail shell stuck inside the return wand. They are really fine bubbles, not causing any issues....just wondered if this was normal?

Thank you, Mike

[Parrothead]

Keep the water level 2 - 3 inches above the return pumps intake, I think you might be sucking some air into the return pump when your water level gets low in the sump

[ToddTT]

Micro bubbles. People go through lots of trouble to try and minimize these.

Raising the water level in the sump can help, because the bubbles have to travel further down to get into your return pump.

But make sure that your sump will not overflow should the power go out. If you haven't already, turn off your pump to see how the water level will rise in your sump, as it siphons from the main tank. Figure out the highest safe water level for your sump, and put a mark on the outside of your sump as a reminder.

A popular option is to set up a baffle in your sump, three walls that the bubbles have to travel over, then under, then over again, before having a chance to get to your return pump.

I've also heard of people using filter socks on their return, but that sounds like a clog (or reduced flow) waiting to happen.

The source of these bubbles is often a protein skimmer. My skimmer has output that is like a bubbly waterfall, which I put a sponge filter directly underneath, and this has helped in my case. A lot of the bubbles are trapped and pop before getting far.

Or... just enjoy the bubbles. ;)

[Ninong]

One potential source of very tiny air bubbles coming out of the return would be a 'leak' in the plumbing between the return pump and the return. If there is a very tiny opening anywhere in the connections into and out of the return pump or anywhere else between the pump and the return, then air will be sucked in -- sort of a venturi effect -- and it will show up as extremely tiny air bubbles coming out of the return(s).

See if you notice any salt creep anywhere in the plumbing connections. Wipe off any salt creep and then go over that connection (on the outside) with something to try to seal it off better. I can't remember right now exactly what I used but it was some sort of sealant. I just sort of went over all of the connections into and out of the return pump and between the return pump and the returns. All I know is that I finally got rid of the extremely tiny air bubbles after three or four months of aggravation.

Good luck.

[Bloodydecks]

all good info above.

Another possible cause that i have come across many times is the clamps on the return hose are not tight enough, and allowing for just a tiny amount of air to be sucked in. Make sure your hoses are well attached to the hose bards and clamp those sucker down tight. If you are using the plastic squeeze on type, use channel locks to squeeze them tighter....if you are using the metal screw type, make them tighter.

If you have a skimmer, or it you are getting bubbles from the overflow (return to the sump hose), use filter floss or pads or sponges some where in between the pump and the return, creating a wall that will trap the bubbles...

also, make sure your intake is as far away from the return as possible.
Also, if you can, take 90 degree hose barb, and screw it into the intake of the pump, and angle it so it pointing down, this will allow for the pump to take in water at the lowest possible level in the sump, allowing more bubbles to gas out/float out.

[mlovelace]

Thanks guys! I will keep an eye on everything mentioned. I just changed the return hose which helps keep the pump at the very bottom of the sump. The pump is on the opposite end of the overflow (in) coming into the sump. I did add more water and it is almost to a non existence amount now. If I keep the water this high, I will need to put another sponge in to help filter the water prior to being returned by pump. I am a little concerned about my filtration once I add fish. As it is right now, I have the water going over one fiber;) filter, through the skimmer, through a sponge, then returning to the tank. Does this sound like enough?

Thank you, Mike

[Parrothead]

Plenty, just keep those fitler pads clean

[metalhead]

all good info above.

Another possible cause that i have come across many times is the clamps on the return hose are not tight enough, and allowing for just a tiny amount of air to be sucked in. Make sure your hoses are well attached to the hose bards and clamp those sucker down tight. If you are using the plastic squeeze on type, use channel locks to squeeze them tighter....if you are using the metal screw type, make them tighter.

If you have a skimmer, or it you are getting bubbles from the overflow (return to the sump hose), use filter floss or pads or sponges some where in between the pump and the return, creating a wall that will trap the bubbles...

also, make sure your intake is as far away from the return as possible.
Also, if you can, take 90 degree hose barb, and screw it into the intake of the pump, and angle it so it pointing down, this will allow for the pump to take in water at the lowest possible level in the sump, allowing more bubbles to gas out/float out.

Bloody, not trying to correct you here so please don't take this the wrong way, but...

In designing the plumbing system for my new tank I did a lot of research. One thing I learned was that any type of restriction on the input side of a return pump is not a good thing as it places more load on the pump and, in extreme cases, can lead to cavitation and pump failure. Keep in mind though that I was researching information on the bigger, Jacuzzi-style pumps so this issue may not even apply to smaller pumps, say a mag-5. Just wanted to point that out.

That said, very good info from everybody here... Follow this advise and your micro-bubbles will soon be a thing of the past. Filter socks on the drain returns work for me but if you go that route make sure you keep them clean as stated above. You will want to thoroughly clean and rinse them at least once per week, same applies to your filter pads.

[Bloodydecks]

Bloody, not trying to correct you here so please don't take this the wrong way, but...

In designing the plumbing system for my new tank I did a lot of research. One thing I learned was that any type of restriction on the input side of a return pump is not a good thing as it places more load on the pump and, in extreme cases, can lead to cavitation and pump failure. Keep in mind though that I was researching information on the bigger, Jacuzzi-style pumps so this issue may not even apply to smaller pumps, say a mag-5. Just wanted to point that out.

That said, very good info from everybody here... Follow this advise and your micro-bubbles will soon be a thing of the past. Filter socks on the drain returns work for me but if you go that route make sure you keep them clean as stated above. You will want to thoroughly clean and rinse them at least once per week, same applies to your filter pads.

I assume you are referencing to the 90 degree fitting off the intake. You are right, that this could be an issue with larger pumps, but i think as long at the 90 is the same ID as the pump intake ID, the minor difference in pressure wouldn't be an issue.

I have only done this on smaller pumps..with flow rates less then 3K GPH at zero head pressure.

[metalhead]

I assume you are referencing to the 90 degree fitting off the intake. You are right, that this could be an issue with larger pumps, but i think as long at the 90 is the same ID as the pump intake ID, the minor difference in pressure wouldn't be an issue.

I have only done this on smaller pumps..with flow rates less then 3K GPH at zero head pressure.

Right on Bloody... Wasn't 100% on the smaller pumps but just figured I'd throw that out there.