New setup with Filstar fx2 on 29g. No problems for 24h then gurgling noise correlating with small bubbles agitating in top of cannister. If restart all goes away only to return. Lubricated o-rings but still recurs and no obvious air leak. Doesn't make sense to me. Help. I am going away in a few days and uncomfortable with new setup. Aquar Pharm has not been responsive, altho I assume they will get back some time next week. Thanks.