Some could be coming from both. The 1 micron is not getting everything, and the system is designed to run with water changes. There's no biological filtration, other than plumbing, etc.
Right now, we can't do the massive water changes that it needs because of the meds. I'm looking at John's ClorAm-X to handle ammonia through the med protocol. Just like it's used to culture.
I'm gun shy after the last UV 'issue'.