Noisy sump?

I Just set up a sump on my 40 gallon and I seem to be getting a lot of toilet flushing sound from where my water drains into my sump (hang on back overflow box). It basically gulps causing the water level in it to fall and then fills back up and then gulps again and so on and so on. A straight piece of PVC with holes drilled into it is what regulates the flow. I notice if I cover top opening and top hole (see pic) the noise seems to stop. Is it safe to cover these holes up? If not any other ideas?

 

Is this on the part of the overflow outside the tank? If it's inside, I would imagine you'd want to turn your return pump up a notch to get it to fill the tank farther.

 

No this is on the outside...I have two overflow boxes because my tank does not have a built in over flow. One inside the tank sucking the water and then the one outside that catches it and drops it down to the sump.

 

See new attached pic to see what I am talkin about.
-Thanks

 

Mine does that too....that's normal. You'll get used to it I don't even notice mine anymore. that water is being pulled down fast through that little tube, so it will make noise.

 

try these for some good solutions:
http://www.3reef.com/forums/general-reef-topics/overflow-silencer-quick-question-86048.html


http://www.3reef.com/forums/i-made/herbie-overflow-video-79073.html

http://www.3reef.com/forums/reef-aquarium-articles-how-tos/all-about-sumps-filters-fuges-79852.html

 

http://www.3reef.com/forums/i-made/hofer-gurgle-buster-82256.html

 

You should not be receiving any flushing / toilet sounds from your tank. The hofer gurgle buster telgar mentioned is great. Basically there is an incorrect amount of air to flow ratio, and the air needs to be adjusted to match the flow and the sound will go away. After I went HGB my tank is pretty much silent (minus the Iwaki hum - needs to be cleaned, I suspect).

 

I just did the "herbie" idea on my CPR overflow. More to quiet the noise in the sump, but it would flush once in a while. No more noise with putting a gate valve at the end of the drain and regulating the flow so the overflow box maintains a certain water level. Installed an emergency drain just incase, but everything is working perfect. I maintain the level of water in the overflow and now there is no noisy air going down the drain, no flushing and no noise in the sump.

http://www.3reef.com/forums/filters-pumps-etc/modified-cpr-overflow-pics-89609.html