Bubbles from one return line

azcraig · 07/12/2008, 09:41 AM

I recently set up my 200 gal reef tank w a 60 gal sump. I have two external Little Giant return pumps and a closed loop with an Iwaki. One of my returns is blowing small bubbles into the tank. I dont' see any bubbles in the sump near the intake (which is only 6" or so from the other intake for the return that has no bubbles) that could be getting sucked into the display tank. What could be causing the bubbles?

rockworm · 07/12/2008, 10:12 AM

I assume thaqt you are saying the two return pumps are receiving water from a common sump and that each is pushing water a separate return in the tank. If this is the case, my first check would be all joints and fittings in the return line that has bubbles. There may be a small enough leak that air is getting in the joint but water is not dripping out. I had this issue on a previous tank. Problem is it is hard to find if you have a lot of joints and fittings.

Good luck.

azcraig · 07/12/2008, 10:19 AM

Thanks! I'll try it. Would it be just on the intake side of the pump?

azcraig · 07/12/2008, 11:02 AM

Could it be the pump?

rockworm · 07/12/2008, 11:15 AM

I had to trace right from the input to the pump through the in tank return. For the life of me, I cannot remember where my leak was. And yes, it could be the pump, given it is external. I would check the connections to the pump. The last area I would check would be the pump itself. Usually leaks in the pump will show water drip.

scott11 · 07/12/2008, 12:07 PM

i had the same problem. I turned off all the equipment except the pump, and listened to the plumbing very closely (my ear down near the pipe). I could hear the air being sucked in. I coated that joint with silicone, no more bubbles!

azcraig · 07/12/2008, 12:23 PM

Well...after doing some silicone coating of my own with no luck, it turns out that the anti-siphon hole in the elbow of the return at the top of the overflow on the bubbling side was causing the problem. I don't know why, since the other side is okay, but if I plug it the bubbles stop. I'd like to keep that hole open so I don't start a siphon if the pump stops...

scott11 · 07/12/2008, 12:28 PM

i also had a similar issue, where the anti siphon holes were making too much noise. I plugged them and now I keep one of my outputs close to water level. Once the pump goes off, I drain back to the sump untill that return breaks the water level. Is is only about 1/2" and my sump can handle the extra water.

07/12/2008, 09:41 AM	#1
azcraig Registered Member Join Date: Jan 2008 Location: Chandler, AZ Posts: 136	Bubbles from one return line I recently set up my 200 gal reef tank w a 60 gal sump. I have two external Little Giant return pumps and a closed loop with an Iwaki. One of my returns is blowing small bubbles into the tank. I dont' see any bubbles in the sump near the intake (which is only 6" or so from the other intake for the return that has no bubbles) that could be getting sucked into the display tank. What could be causing the bubbles? __________________ Courage is not the absence of fear, but the mastery of fear. Current Tank Info: 200 gal reef w/60 gal sump, 55 gal reef

07/12/2008, 10:19 AM	#3
azcraig Registered Member Join Date: Jan 2008 Location: Chandler, AZ Posts: 136	Thanks! I'll try it. Would it be just on the intake side of the pump? __________________ Courage is not the absence of fear, but the mastery of fear. Current Tank Info: 200 gal reef w/60 gal sump, 55 gal reef

07/12/2008, 11:02 AM	#4
azcraig Registered Member Join Date: Jan 2008 Location: Chandler, AZ Posts: 136	Could it be the pump? __________________ Courage is not the absence of fear, but the mastery of fear. Current Tank Info: 200 gal reef w/60 gal sump, 55 gal reef

07/12/2008, 12:23 PM	#7
azcraig Registered Member Join Date: Jan 2008 Location: Chandler, AZ Posts: 136	Well...after doing some silicone coating of my own with no luck, it turns out that the anti-siphon hole in the elbow of the return at the top of the overflow on the bubbling side was causing the problem. I don't know why, since the other side is okay, but if I plug it the bubbles stop. I'd like to keep that hole open so I don't start a siphon if the pump stops... __________________ Courage is not the absence of fear, but the mastery of fear. Current Tank Info: 200 gal reef w/60 gal sump, 55 gal reef

07/12/2008, 10:12 AM	#2
rockworm A-counting guy Join Date: Jul 2004 Location: Ottawa, Ontario, Canada Posts: 673	I assume thaqt you are saying the two return pumps are receiving water from a common sump and that each is pushing water a separate return in the tank. If this is the case, my first check would be all joints and fittings in the return line that has bubbles. There may be a small enough leak that air is getting in the joint but water is not dripping out. I had this issue on a previous tank. Problem is it is hard to find if you have a lot of joints and fittings. Good luck.

07/12/2008, 11:15 AM	#5
rockworm A-counting guy Join Date: Jul 2004 Location: Ottawa, Ontario, Canada Posts: 673	I had to trace right from the input to the pump through the in tank return. For the life of me, I cannot remember where my leak was. And yes, it could be the pump, given it is external. I would check the connections to the pump. The last area I would check would be the pump itself. Usually leaks in the pump will show water drip.

07/12/2008, 12:07 PM	#6
scott11 Registered Member Join Date: Aug 2003 Location: Scottsdale AZ Posts: 1,960	i had the same problem. I turned off all the equipment except the pump, and listened to the plumbing very closely (my ear down near the pipe). I could hear the air being sucked in. I coated that joint with silicone, no more bubbles!

07/12/2008, 12:28 PM	#8
scott11 Registered Member Join Date: Aug 2003 Location: Scottsdale AZ Posts: 1,960	i also had a similar issue, where the anti siphon holes were making too much noise. I plugged them and now I keep one of my outputs close to water level. Once the pump goes off, I drain back to the sump untill that return breaks the water level. Is is only about 1/2" and my sump can handle the extra water.