Microbubble issues from a Blueline 55 HD pump

[seapug]

I've been attempting to address a microbubble problem I'm having with my plumbing. Pump is an external Blueline 55 HD, about 8 months old.

I've slathered every PVC joint between the sump bulkhead and the pump with Silicone glue and also replaced a union. Still no fix. Tank has dual returns and both are spewing equal amounts of bubbles so I can only assume it must be coming from the suction side of plumbing. Before I rebuild the entire suction side of the plumbing, I want to make sure the problem isn't coming from the pump itself. Anyone had any similar problems/experiences with these pumps? Thanks....

 

[joekidwell]

i know im new to this and all and this might sound stupid but blow into your returns while someone sprays all the joints with water looking for bubbles, or better yet use an air compressor if u have access to one. you would have to block the inlet to the pump with something to make sure no air exits that way.

 

[joekidwell]

is there any chance there could be micro bubbles in your sump?

 

[seapug]

There are very few bubbles in the sump and none in the last compartment where the bulkhead is but the returns are starting to look like there's a venturi somewhere in the system. The air pump idea might be worth trying, but there's a slightly complex manifold where the return line splits that might make that a bit difficult. When the pump is turned off there are no leaks so it must be an extremely small gap that forms under negative pressure somewhere on the suction side. I've never removed the pump and disassembled it, but I'm a little suspicious there's a seal or gasket in the pump housing that may be out of alignment.

 

[joekidwell]

Wouldnt hurt to open it up and check it out, apply some silicone lube to all the gaskets maybe that would help.

 

[sirreal63]

...but I'm a little suspicious there's a seal or gasket in the pump housing that may be out of alignment.

I would be suspecting the same thing. Can you reverse the pressure from the return? An air pump to force water back down the return so that you can check where the water is coming from? Of course you will have to shut the manifold down but it would show the leak.

 

[seapug]

I would be suspecting the same thing. Can you reverse the pressure from the return? An air pump to force water back down the return so that you can check where the water is coming from? Of course you will have to shut the manifold down but it would show the leak.

Each line off the tee has its own gate and ball valve so that wouldn't be impossible to do, but as I mentioned before, there are no leaks in the plumbing when the pump is shut off, so I suspect it's a tiny air leak somewhere that only forms under negative pressure on the suction side of the pump. The plumbing run from the sump bulkhead to the pump is not complex and is currently slathered in silicone glue, so that's why I'm suspecting the pump.

I'll just have to disconnect it this weekend and open it up to have a look. If that doesn't do the trick I'll just rebuild the entire return plumbing.

Can't wait to get rid of these bubbles! :headwallblue:

 

[kenith]

I had the same issue with my external pump some years back. I used the Eheim 1262 with a threaded PVC for the inlet side of the pump. I ended up putting tons of teflon tape to seal it and it solved the issue. Now I just run internal pumps for the ease Hth

 

[seapug]

I had the same issue with my external pump some years back. I used the Eheim 1262 with a threaded PVC for the inlet side of the pump. I ended up putting tons of teflon tape to seal it and it solved the issue. Now I just run internal pumps for the ease Hth

yeah, I actually replaced the entire union on the threaded inlet side of the pump and used both teflon tape and a blob of silicone glue on the threads. No success there. I used a submersible pump on my old tank but needed something a little beefier on my new one. But if I can't solve this problem I might resort to ditching the external and sacrificing some turnover.

 

[sirreal63]

It isn't the plumbing I was expecting to show the leak, but the pump housing itself, if that is where it is drawing in air from. It may not reveal itself from reverse pressure, but if it did it would be nice to know exactly where the issue is instead of rebuilding the whole pump. I hope it ends up being an easy fix.

 

[seapug]

It isn't the plumbing I was expecting to show the leak, but the pump housing itself, if that is where it is drawing in air from. It may not reveal itself from reverse pressure, but if it did it would be nice to know exactly where the issue is instead of rebuilding the whole pump. I hope it ends up being an easy fix.

Ah, I see...but I'm thinking it'll be easier to remove the pump and inspect the seals. I'm sure it is a simple fix, it's finding the actual source of the problem that's so difficult!

Thanks for the suggestions.

 

[seapug]

Finally got the issue resolved. I disconnected the pump, opened it up and cleaned out the inside. I noticed a couple bolts on the impeller housing were a bit loose. When i put it back together and tightened up all the bolts and restarted the microbubbles were gone. What a relief! So nice to have clear water again.

 

[sirreal63]

That is good news, I am glad it was a simple fix.