Quick follow up here. I did the deed tonight and was shocked at the filth I observed in there. It bothered me so much that I ended up taking apartment all plumbing for a deep clean. I'm wondering if the junk/organisms in my plumbing is what's responsible for my ongoing tank ailments...
I setup my tank in February and have considered cleaning my valve, how long has your tank been in operation and can I assume this is the first time you have cleaned yours?