Bubbles in Closed Loop

[plutoniumJoe]

Everything has been going great for about 14months then almost over night I started noticing micro bubble in my tank. I initially that it was due to increased fan speed over tank(not). The bubbles seemed to be coming out of the closed loop. The loop is an OceansMotion 4way run off a Reeflo Dart. I checked all the pipes and there does not seem to be anyway for air to be getting into the loop.

The only other thing I can think of is that my inlets(3 X 2inch) are getting clogged by coralline algae. When I look at the dart it looks like there is a washer that occasionally travels the length of the shaft than settles back down towards the motor side.

Any ideas are appreciated.

Joe

[Dez]

Maybe re-plumb the intake of the closed loop. Any Teflon taped fittings. This happened to me a couple of times a few years ago. It's annoying I know. Glued fittings should be fine.

[The Grizz]

Has to be a very small air leak into the CL, also happened to me. Removed the CL pump and re tefloned the threaded fittings, bubbles gone.

[Lampshade]

Wrap a wet towel or cloth around the fittings one by one, if the bubbles stop you've found the leak. For the pump to cavitate and cause bubbles it would have to be VERY restricted, you would have noticed the reduced flow before the bubbles.

[untamed]

Try what has been mentioned... But if that fails, open up the impeller of the pumps. I've had debris stuck in the impeller vanes and it doesn't take much to cavitate the flow and cause micro bubbles.

Not theory. It happens to me all the time. My system has two OM4ways on two Darts.

[sphelps]

It's also possible that the intake plumbing has become more restricted resulting in a lower pressure at the pump intake, if the pressure is low enough it can actually liberate dissolved oxygen. To test for this just throttle back the pump output halfway, if the bubbles stop this is likely the issue. I've seen this happen with these pumps when people don't plumb large enough pipes and bulkheads. Untamed is also correct regarding cavitation which is essentially the same thing, a good cleaning could fix things.

If not it could also be the seal on the pump, anywhere you notice salt creep could be a potential leak.

[plutoniumJoe]

Thanks for all the reply's it is nice to have the community for more than just a buy/sell board.

I will try the throttling back.

Originally Posted by sphelps

It's also possible that the intake plumbing has become more restricted resulting in a lower pressure at the pump intake, if the pressure is low enough it can actually liberate dissolved oxygen. To test for this just throttle back the pump output halfway, if the bubbles stop this is likely the issue. I've seen this happen with these pumps when people don't plumb large enough pipes and bulkheads. Untamed is also correct regarding cavitation which is essentially the same thing, a good cleaning could fix things.

If not it could also be the seal on the pump, anywhere you notice salt creep could be a potential leak.

and then work my way up from there. I really hope it is not a joint above the true union. I dreamt of Rubber Maids and total tank cleanouts last night.

** If I take apart the impeller do I need a new seal kit?

[intarsiabox]

Originally Posted by plutoniumJoe

** If I take apart the impeller do I need a new seal kit?

Carefully remove the impeller and take a look at both seal faces, if there are any scratches, chips or uneven wearing then you should replace the seal. If after you clean out the impeller the seal faces look good take a Q-tip soaked in a bit of rubbing alcohol and clean the seal faces before replacing the impeller. Even if all looked good the seal may still leak as they don't always mate up perfectly if they've been used for a while. You may be able to buy the mechanical seal at a pump rebuilding company for about $20 rather than ordering an actual reeflo seal if that is any easier for you.