Reurn nozzle in overflow box

[jp1986]

Have an 8ft wide 300 gallon that I got used. The overflow box is located on the right side. There is a return nozzle coming out of the overflowbox, as well as one on the left hand side of the tank on the back wall. With the one coming out of the overflow box, I feel that would kind of mess with what water then flows into the overflow. I will have a couple mp40s and a Octo Pulse 4 for flow throughout the tank. I am wondering if just using the return on the left would be enough or if I am better to use both?

 

[JumboShrimp]

I get what you are saying. Like pushing overflow water 'away' from the overflow you are wanting the water to head 'toward.' I would point the return nozzles down deeper into the tank. Then get a cheap powerhead for the far end of the tank, and point it at the surface.

 

[UncommonSense]

The wave makers are moving probably at least 10x the water of the return pump, so whatever is pumped into the tank by the return pump(s) is rapidly mixed with the rest of the display’s water!

I’d say you’re mixing 95%+ of the water returned from the sump into the DT with your current configuration!

It is worth noting that submerging your return nozzles too far underwater (with no other form of anti-siphon device) can easily cause the sump to overflow during a power outage/return pump shutdown!

 

[JumboShrimp]

That's true, about possible sump overflow, @UncommonSense!! My bad. My return nozzles are always skimming the water surface, so I lost focus here. Good catch.

 

[jp1986]

Am I right to assume that by having the left side return nozzle just above the water line, and then the one coming out of the overflow on the right would be pointed down, I would get a siphon break from the left one being out of the water? I plan to split the line coming off the return to supply both the left and right return nozzles.

 

[UncommonSense]

Am I right to assume that by having the left side return nozzle just above the water line, and then the one coming out of the overflow on the right would be pointed down, I would get a siphon break from the left one being out of the water? I plan to split the line coming off the return to supply both the left and right return nozzles.

Yes, that works great! I also recommend drilling a 1/4” hole in one of the loc-line segments on the left side return, near the bulkhead, near the water’s surface, facing in a direction where it won’t spray water up in the air…

This functions as your siphon break if the left side nozzle gets bumped/submerged significantly at any point! — we’ve gotta stay ahead of Murphy’s law in this hobby!