Return/output nozzle suggestions

[vincel892]

For those with 700+ gallon tanks, what size returns are you using and what type of nozzle ?
Do the eductors that claim to increase flow actually work ? Im considering using one of those swirl eductors but not sure what size I should go with. I've only been able to find eductors with max diameter 1". Are there larger ones available ?

 

[pacu mom]

Consider Venturi return nozzles which are for 1.5" pipe. I like that the flow can be directed to wherever you want it to go.
Here's what they look like.

black venturi return nozzles - Google Shopping

www.google.com

We have one on our small 300 gallon tank and plan to use at least four Venturi returns on the big tank (which is not set up yet). Not only do we get the "venturi" effect, but the system spits out air, and is the only aeration on the tank.


Here is very old video at the end of a water change. You can see that even with the tank refilled, the system still spits out air.

 

[pacu mom]

I didn't answer your question completely. Our big tank has two external overflow boxes and has holes for eight 1/2" Locline returns. Since the sump is for redundant filtration only, I'm not concerned about the small returns. My main biological and mechanical filtration will be via these pipes.



The returns will be staggered in height, and with the ability to direct the flow, we should get the current to go where we want it to go.

 

[TheWolfman]

Those venturi returns are cool. If my tank wasn’t in my living room I would consider running them. I’m running 1-1/2” black Abs street 45’s with a 1/4” hole drilled just above the water to prevent back syphon. I can aim them at the bottom and keep the poo off it. With the amount of gph your going to running I don’t think your going to have flow issues.