Help with tuning output and input on sump

[elcapitan1993]

So I just set up my sump, I have 1 h2overflow with stealth box as my intake i plumbed it with a gate valve to adjust it, I bought a dc pump rated for 1200 gph, but no matter how many adjustments I make to either the water level in my aquarium or sump raises and doesn’t level out, I cannot find anything online about how to fix this and I have been sitting at my sump adjusting it all day so it doesn’t overflow, please help

 

[lapin]

I assume you have this and it says its rated for 1200 gph

H2Overflow® Aquarium Overflow System - Custom Aquariums

The patent-pending H2Overflow is an elegant, quiet, efficient way to get water from your aquarium to your sump tub, maintaining your aquarium water overflow.

www.customaquariums.com

Steps:
Fill the tank until it starts to go down the overflow.
Note: The overflow pipe needs to be at the water level surface in the sump or just above it Too deep and the pipe will not purge air and the tank can overflow.
Fill the sump from where the water enters it form your overflow pipe. (first chamber, before the baffles)
Fill it until you have about 2 to 3 inches of water above the return pump intake (return chamber)
Now open the the gate valve all the way.
Turn on the pump. If they are correct in stating 1200gph it should handle your pumps output.
You may have to add some water to the sump to make up for water that moved into the pipes . Do not overfill. When the pump is off some water will drain back into the sump

 

[elcapitan1993]

Yes that is what I have and I don’t recommend you get it, the plastic on the overflow box is so warped I cannot fit the pipes in the back to make a herbie overflow, matter of fact I cannot fit any pipes in the back of the box, I will give that a try thank you