I have an AGA overflow kit. First I had siphoning, not enough air gets in the air hole so it starts a siphon and sucks water until the level goes down to the strainer, then it sucks air and the water level rises again. By using a ball valve on my return I could have slowed the return rate to something that wouldn't start a siphon. But I drilled some extra holes in the top of the standpipe. That stopped the siphon, but it was noisier. I think I got used to it but my overflow cover may help some. There are definitely quieter ovflows out there to be had than the AGA one. Also I have quite a bit of noise in the drain and my
skimmer took a while to quiet down. Some people use things like spaflex tubing to help quiet the drain and return lines.
