Bubbles from return pump?

jonnybravo22 · 01/30/2010, 12:53 PM

Wondering if anyone knows what causes bubbles from return pump? i know it could be anything in the return line plumbing so not easy to just state a cause but has anyone ever solved an issue of microbubbles in the return line. my return line seems to burp out a mass of microbubbles every hour or so. it's not constant, it happens sporadically.

could this be the result of a damaged pump from running dry/partially dry at some point in the past? is it more likely that it isnt the pump?

pump is an eheim 1250.

serum153 · 01/30/2010, 02:24 PM

How long has the sump/plumbing been set up. I believe it takes 2 weeks to build up a coating which should reduce the bubbles some. I run a 1262 and adapted it it to a 1 inch return line. I know exactly what you are talking about when the top gets exposed to air due to not topping off in time and while that does create a lot of microbubbles at the time, it most likely didn't do harm to the pump as the intake is a little further down. Are your baffles doing their job? I take a flashlight and monitor how many bubbles are in the overflow area and then how many over the first baffle, etc... How big is your return plumbing? You should be using at least 3/4" in my opinion.

jonnybravo22 · 01/30/2010, 05:44 PM

yeah the baffles are doing their job. i've had the setup with this pump/plumbing for about 8 months so its well broken in.

yeah it's exactly like when the pump runs with the top exposed and starts shooting microbubbles, which i've let happen a few times accidentally by taking water out and not paying attention to the sump, but the problem now is that it happens when it's covered w/ water in short spurts...so i'm thinking it is something with the pump. yes i'm using 3/4inch plumbing.

lots of good thoughts, i appreciate them. still at a loss unless the pump is damaged.

richpoolboy · 01/30/2010, 06:04 PM

I would like to look at the plumbing job to be sure but it sounds like you have a vacume loop in the plumbing somewhere

jonnybravo22 · 01/30/2010, 07:02 PM

what does that mean? water is being pulled back out / down towards the pump as it's being pushed out / up into the tank?

interesting theory, could be happening w/ my setup if that's what you mean, i'll see about addressing it if that's the case.

01/30/2010, 12:53 PM	#1
jonnybravo22 Registered Member Join Date: Dec 2008 Posts: 1,128	Bubbles from return pump? Wondering if anyone knows what causes bubbles from return pump? i know it could be anything in the return line plumbing so not easy to just state a cause but has anyone ever solved an issue of microbubbles in the return line. my return line seems to burp out a mass of microbubbles every hour or so. it's not constant, it happens sporadically. could this be the result of a damaged pump from running dry/partially dry at some point in the past? is it more likely that it isnt the pump? pump is an eheim 1250. Last edited by jonnybravo22; 01/30/2010 at 01:03 PM. Reason: pump description

01/30/2010, 02:24 PM	#2
serum153 Registered Member Join Date: Mar 2007 Location: Reno Posts: 584	How long has the sump/plumbing been set up. I believe it takes 2 weeks to build up a coating which should reduce the bubbles some. I run a 1262 and adapted it it to a 1 inch return line. I know exactly what you are talking about when the top gets exposed to air due to not topping off in time and while that does create a lot of microbubbles at the time, it most likely didn't do harm to the pump as the intake is a little further down. Are your baffles doing their job? I take a flashlight and monitor how many bubbles are in the overflow area and then how many over the first baffle, etc... How big is your return plumbing? You should be using at least 3/4" in my opinion.

01/30/2010, 05:44 PM	#3
jonnybravo22 Registered Member Join Date: Dec 2008 Posts: 1,128	yeah the baffles are doing their job. i've had the setup with this pump/plumbing for about 8 months so its well broken in. yeah it's exactly like when the pump runs with the top exposed and starts shooting microbubbles, which i've let happen a few times accidentally by taking water out and not paying attention to the sump, but the problem now is that it happens when it's covered w/ water in short spurts...so i'm thinking it is something with the pump. yes i'm using 3/4inch plumbing. lots of good thoughts, i appreciate them. still at a loss unless the pump is damaged.

01/30/2010, 06:04 PM	#4
richpoolboy Registered Member Join Date: Jan 2010 Location: Tucson Posts: 240	I would like to look at the plumbing job to be sure but it sounds like you have a vacume loop in the plumbing somewhere

01/30/2010, 07:02 PM	#5
jonnybravo22 Registered Member Join Date: Dec 2008 Posts: 1,128	what does that mean? water is being pulled back out / down towards the pump as it's being pushed out / up into the tank? interesting theory, could be happening w/ my setup if that's what you mean, i'll see about addressing it if that's the case.