no, just a bad error from me during water changes and internal filter quarterly clean up... Like usual, every 3-4 months, I clean the anaerobic bottom layer of the filters. Taking out black mud and NH3 from this ****.
But unlike usual, I was too concerned and worried by changing work (on April 1st) and with mean subjects from my boss, and I refilled with cold water DIRECTLY IN THE BOTTOM OF THE FILTER, in the anaerobic zone, not only releasing NH3, NO2 and mud in the whole tank, but causing also a lethal drop of oxygen.
Of course, as Murphy is always around, I made the water change on Thursday morning, and left for job till Friday night, when I discovered (at first smell) the disaster.
thug life... and newbie ****... after 20 years of fishhobbying, I'm still producing **** sometimes...