Cor-20 "ideal" speed for RedSea 425 XL v3

[BryanM]

I know the return and cor-20 need to be matched up... But I was reading another thread where the OP ran his cor-20 at 40%, if I do that the output is a lot, and quite loud. I'm sure I can get the return flow setup to match, but this seems unacceptable loud.

Currently I have it set to 25%, which still makes some noise, but is quite a bit more pleasant.

Is there some standard method to setting this? Thanks

 

[Bartanto]

My Cor-20 on my 525 at 46% flows at 420 gph to display and is virtually silent. Are you running it hard plumbed? If so a 12” silicon tube from pump to returns may help in the noise department. With your apex you can set your ‘IQ’ level adjustment to basically change arbitrary mins/maxes - but that won’t change the sound.

 

[BryanM]

My Cor-20 on my 525 at 46% flows at 420 gph to display and is virtually silent. Are you running it hard plumbed? If so a 12” silicon tube from pump to returns may help in the noise department. With your apex you can set your ‘IQ’ level adjustment to basically change arbitrary mins/maxes - but that won’t change the sound.

The pump is silent, is the water coming back in to the tank that makes noise.

 

[Bartanto]

The pump is silent, is the water coming back in to the tank that makes noise.

Ahhhh, the drain is loud…that’s a different story. Check out the Red Sea operators manual on-line for how they recommend setting the diaphragm valve. If it’s super loud the valve is probably too wide open. If you have enough water in the system SLOWLY close the drain until water in the overflow 1 cm. Below the emergency drain.

 

[BryanM]

Ahhhh, the drain is loud…that’s a different story. Check out the Red Sea operators manual on-line for how they recommend setting the diaphragm valve. If it’s super loud the valve is probably too wide open. If you have enough water in the system SLOWLY close the drain until water in the overflow 1 cm. Below the emergency drain.

The return in to the display tank is loud.... I don't mind the sound of a "babbling brook", but if I turn the cor-20 up to 40%, the sound in the display tank is more like a raging river.

 

[Bartanto]

Are the rtn nozzles adjustable? Can you bury them further under the water line?

 

[BryanM]

Are the rtn nozzles adjustable? Can you bury them further under the water line?

They are, and I thought I had them pointed as low as they would go, but thankfully I was wrong. Now the cor-20 is running at 50%, and still quieter than it was before.