THat is just what I have heard I do not have one. If it is spewing out the top there is a reason something aded to the tank or a spawn of some sort. even bad skimmers don't actup without a reason. a blockage some where in the skimmer that you can't see. I have a flexable tube cleaner and I can push it through the tubes so I know they are clean. I would say the return has some thing in it or a buildup of some sort. that is what I would check. I have seen alot of posts on many forums that people like these skimmers.
The joys of being layoff you can look for work from home crouse the net for fish stuff and talk on the forums.

Bill