Introduction
My name is Jerry and I have been a serious fish-keeper for 2 years now, but off and on for 25 years before that. I currently have 5 tanks running - a 125G, 2 55G’s, a 30G and a 29G + some small fry tanks. My primary focus has been on tropical community tanks. Lately, I have taken an interest in angel fish and dwarf cichlids. I have 2 successful breeding pairs of angels, and have had some success getting blue rams to breed, but I have had no luck with keeping the either the adult rams or the fry alive for any extended period of time.
My background is in industrial engineering and computer science, but I am now focused on technology risk management, disaster recovery and that sort of thing. That background has made me look at and question many things that are commonly accepted, dreaming up experiments that I have yet to undertake.
First on my list is to determine where the nitrogen oxidizing bacteria actually reside in an aquarium. It’s commonly accepted that transferring filter media from an established tank to a new tank will either immediately cycle or dramatically shorten the time to cycle a new tank. I have no less than 6 real world experiences where this did not happen. My experience has been:
- Move filter media from a cycled filter (with appropriate due care) to a new filter. Result: new tank is NOT cycled and must proceed with the cycle per normal.
- Move the whole filter from a cycled tank to a new tank. Result: new tank cycled immediately.
So, in my experience, the media does not appear to be where a preponderance of the bacteria are living. I have been theorizing that the bacteria are primarily living on surfaces that have some kind of turbulent flow over them, such as discharges, pump impellers, etc. If I am correct, some amount of bacteria probably live at the very top of the filter media of a standard HOB filter, where water is somewhat turbulent.
I have been thinking of a some valid experiments to help determine where the bacteria live in different conditions. If you have any input on that, please post a comment. I will conduct the test once I have a good plan in place.