Sound effect in my fishroom????

I'm renovating my fishroom into a fully automatic centrilized system. I'm scratching my head for one of my breeding system which is located on the upper level eye level powered by a 5000L. water pump. It has 6 tanks in series. There is a wave and rumbling sound in the water return pipe which sounds like an ocean. Air are being drawn into the system and unable to escape. I actually like that sound effect but its kind of annoying after a while. Please give me some pointers to solve this problem. I have added a pipe to the last tank before the drop to the sump hoping to vent the air bubble to the atmospher but it doesn't work. The only way to stop it is to turn down the wate flow to each tank. With the low flow I'm still able to fill up the whole tank in 15 min. Water is able completely turn over 4 times an hour.
Jimmy.

[ronrca]

I have added a pipe to the last tank before the drop to the sump

Do the same for all the tanks! I use a T instead of a 90 and a length of pipe! You can also use air line, drill a small hole, insert air line and silicon!

Check out my yahoo pics for the T connector! I had the same kind of rumble and now its gone! ;D

[Smokey]

I have had the same sound/situation. Allowing the air to escape - as it flows into the return pipes - will quieten everything down to a soothing level. Ron's suggestion will do the job..

Smokey

Problem solved. A stupid mistake. The pipe I added before the drop will not work if the cap is not drill to let air out. I knew there is a simply solution. Thanks Ron.
Jimmy.

[ronrca]