I will give you links to a site that will show you how to make the perfect stand pipe....nice and easy!!! Just change the pipe size to whatever your bulkhead is!!
http://mywebpages.comcast.net/domitron2/HGB/HGB.html
Also for the pipe going into the sump sumerge the pipe about 1" to 2" into the water, Then right were the pipe enters the water in the sump drill 2 or 3 - 1/2" holes.....If you do these 2 things I garuntee that it will be super quite!!!!
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500G Mixed Reef

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Electrician, Electronics Technician, I can help with any electrical questions you might have!!
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Kevin