Passive Overflow Plumbing Question

[Reef Rhino]

Setting up a 45 gallon Annex to be plumbed into my existing Reef system and sump. Display tank (75g) and another Cube (32g) tank currently use the 50g sump and the third new tank (45g) will be added. Display uses a quiet Bean Animal drain and the Cube uses a Herbie, also quiet.

For the third added tank I am hoping to just use a passive overflow using a two (2) simple screen / strainers and 1" pvc and 1" vinyl drain lines through the two bulkheads. Tank return will be a 3/4" line and drains will be two (2) 1" drains (1.5" bulkheads but reduced to 1") back to the sump. Return can be low flow because the tank itself will have aggressive flow through a gyre and I really just want the water turned over through the sump for dosing, skimming, heating, overall system water stability, etc. The 45g will be across the room so I may add a small heater just to keep Siberia warm enough.

The question is how to best to quiet the passive pvc and 1" hose drains so that it isn't too loud? Looking for suggestion on the drain size. Simple would be two up-turned 1" pvc (45 or 90) but any ideas how to avoid suction, slurp, or water crashing down and back in to the sump?

Thanks

 

[TX_REEF]

I think you’ll be happier if you drill and install a small 2-drain overflow box, there’s no sure fire way to silence upward turned elbow drains unless they’re both full siphons

 

[Reef Rhino]

Yes and Thanks. I had the Tank drilled to receive a Synergy Shadow in case it is needed. One problem is a long run of hard plumbing and possibly horizontal plumbing that will block a water heater and other sump and tank obstacles and logistics. Maybe vinyl tubing would work for certain sections and allow it to be more modular and removable.

If I do go with upturned pvc tubes and a passive gravity flow, do a small holes and inserted airlines drilled in the elbows off the back quiet the drain like a durso?

I would not mind some noise. I just want to avoid the rhythmic suction and slurp effect.

Thanks