Ca reactor trouble - suggestions ?

[Delphinus]

How old is the media? It might not actually be a leak (well, it could be, but not necessarily). It could also be that the media is starting to compact and the pump is unable to recirculate - thus in the area of low pressure (suction side of the pump) the bubble forms and grows. I find if I let my media go too long I get this phenomenon. It's really hard on your pump too BTW.

Also I'm curious how you have your reactor fed? Typically the effluent rate should not be affected by a bubble in the recirc chamber. That's another reason I'm thinking it may be media clogging...