I need some help from the community on an issue I have been trying to tackle, otherwise the tank is looking great! Full shot below. Looking a little packed, but many of the zoas are going to the classroom tank or eventually DBTC. Anyways, onto the main annoyance - MICROBUBBLES.They are not taking over the whole look of the tank, but are just a minor disturbance to the overall aesthetic of the display.
They are clearly coming from my return pump, and before you ask it is not the skimmer, it is not vortexing air from the surface, and I have tightened down all the unions on the way up. My strongest hypothesis after reading a whole bunch online is that my pump is oversized for my return line (sicce syncra 4.0 pushing into a 3/4 in return line) and is causing cavitation due to..and the physics are lost on me here...negative pressure blah blah...my background is marine biology so I am great at identifying biological issues but terrible with the physical science of reef tanks. Help!
Possible courses of action:
1) I do have a manifold coming off the return line that is currently closed, usually goes to my chiller but I took that offline for the winter after cleaning it. I believe I still had a few microbubbles coming from the return even when the chiller was taking some of the flow, which was just pumped back into the sump. Should piping soft tubing onto the manifold theoretically help?
2) Just get a smaller pump? I have the syncra 4.0 on the lowest setting, but I am a big fan of turnover rate between the sump and display.
3) The nuclear option, re-plumbing the return line with 1-inch PVC? Does this matter if my IM-50 return bulkhead is still 3/4 inch, and I would need a reducer before the return bulkhead up top?
Any thoughts or advice you have are appreciated!
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