Flushing Overflow Box/ Bubbles in sump

[Happyfeet]

Hey guys, I have a CPR overflow box and I built a stockman stand pipe to quit the crashing sound of water flooding into the empty overflow box.
Since installation I've tried a couple variations all with the same results. (You will have to excuse how ugly the stockman standpipe is, Home Depot doesn't actually carry the correct parts so I had to saw apart parts they had and make my own to make it work)
The overflow box flushes (regardless of how many holes I put in the cap, I started with 1 hole 1/16th size and increased to 4 holes 1/16th size, but it was still flushing so I increased to 3 1/16th and 1 1/8th size hole and the same thing happened. I widened another 1/16th hole to 1/8th and it started to make a gurgling noise. (Right now I have all but one 1/8th hole covered with Teflon tape to stop the gurgling sound.
The another problem is in the sump its violently shooting bubbles, to the point where the plumbing shakes.

If I take off the Stockman standpipe it runs smoothly (Minus the sound of crashing water).


(Overflow is empty)



I'm thinking about adding a ball valve at the red X so more water goes over my sheet and expels air that way it might be quieter.



Any ideas on stopping the flushing and the incredible noise from the bubbles?!

[charlie]

Take the stockman out and put a ball valve right below the overflow. I did this on my 80. You can slow the flow down to a manageable rate and stop the noise. It worked for me, hope it works for you.

[Happyfeet]

Already did that, It kept overflowing the display tank =(

[charlie]

What overflow and what return pump?

[Happyfeet]

What overflow and what return pump?

CPR 90 rated at 600GPH
Mag 9.5 return. I have the mag throttled back like half way. It's A LOT stronger than I thought and everyone kept recommending it with the setup I have.
Probably going to try and find a weaker mag. problem is though at 4' the Mag 7 is only rated at 480GPH

[charlie]

Either that or get the bigger CPR. I would put a Mag7 with that overflow, I hope no one here suggested that, and if we did, you have permission to kick our butt!!!!!
What size tank is this?

[Happyfeet]

Either that or get the bigger CPR. I would put a Mag7 with that overflow, I hope no one here suggested that, and if we did, you have permission to kick our butt!!!!!
What size tank is this?

No, no one here suggested that. Though I was tempted to point my finger into the crowd.

[charlie]

If you point at me, I'm ducking!!!