Hi Si and Joshua,
Apologies - I know you've asked any number of questions and I've not had time to absorb them and try to respond or at least comment. Its a big holiday in the US and like lots of other people I'm at the beach and in my case I'm at the mercy getting a free wireless signal etc. Actually, luckily my free wireless (from who know who's beach house, lol) is great but the darn beach house itself is so ancient the electrical sockets keep shorting out and my laptop runs out of juice, plus when the waves are good I of course have to body surf, which is my thing.. or else work on meals since there are 48 of us so there's a lot of eating and cooking, argh
And on top of this I'm sure I'll be much better when I get home as the schedule stays horrible for a while yet. I used to get longer stretches to enjoy following all the threads!
Anyway, Si asked me in particular about the frustration of being in the 3rd phase, waiting for both ammonia and nitrite to clear to zero ppm in 12 hours (after adding 5ppm at the add-hour) and having NO2 still at 0.25ppm one day and then 1ppm the next day and then 0.5ppm the next day. So the question is.. "How can it go backwards?" "How can it seem the colony is big enough to clear 0.25ppm one day and not do it the same the next?"
So here's my answer (based on all the usual junk of a hobbyist, reading articles, reading threads over time etc. so of course I'm not a scientist like Hovanec doing specific bacteria stuff so I could be wrong, but hey!) I feel that you are letting yourself slip into the wrong mindset of thinking of the cycling process and test results as being like "chemistry." In fact it is "biology" and instead of just chemicals and chemical reactions you are measuring, its tiny "animals." Even bacterial cells are -extremely- complex compared to chemical reactions. And a whole little "city" of cells is even more complex than the study of a single complex cell. They just process more NH3 or NO2 one day and less the next. The problem is that your allowing your mental "window" to be too narrow. You're comparing one day to the next day when really its better to average this sorto of thing over several days or even a week and a half or something.
The problem with the darn biofilters is that they are following their own special little world of digging in and creating an effective colony and if conditions are not quite perfect for them then its just slow. We are by no means educated enough about them (even the waste water treatment plant scientists are no more knowleageable and end up learning sometimes from the fish people I think) to really know all the factors. We optimize all the factors we know about but there are no doubt others that will someday be found and will make things better. For some reason, some tanks just don't seem to finish in the 40 to 50 day quicker timeframe and instead go out to about 70 days or so before they finally double-zero at 12.
As you are seeing, this causes even sensible people such as yourselves to go nuts and start dreaming up ways to get around it. Everyone starts to question their initial bioload and feel that if they're not going to stock 100% then why no just go for 3 or 4ppm instead of 5ppm. The problem with this is that its not just bioload you're prepping your bioload for its also just pure time and robustness of the colony so that once you take away the big ammonia source, it will drop back down to match the fish and will not mini-cycle on you. For some reason, the N-Bacs can seem to processing a lot, leaving just, say, 0.25ppm at 12 hours and yet when you do the big water change and get the fish, they will just stumble and mini-cycle on you. There's a couple of members who say you should really get it down to double zeros at 8 or 10 hours after dosing (so they are even more hard-nosed than the little group of me and BTT and Miss Wiggle etc. who have settled on the 12 hour thing) but in my experience (its got to be hundreds of cases OM47 and I have watched) the 12-hour thing plus the qualifying week as been full insurance against mini-cycles.
There are a few cases however where the person has aborted the fishless cycle out in the 50 day and beyond range and the results of what happened are split. In some cases the mini-cycling they got was small to non-existant the it turned out the bacteria were really able to handle the tank from then on. Unfortunately in some other cases, they NO2 spiked rather strongly and they had to do rather a lot of fish-in cycling for it to finish up.
Anyway, I'm still a pretty strong believer in going back up to 5ppm before the end and in the 12 hour plus qualifying week as virtually all the people who have been able to make themselves hold out for this have reported double-zeros from then on with their fish in and very alert, colorful, healthy fish behavior. Aborting early and risking having to do some fish-in is still a possibility on a case-by-case basis but its not ideal.
(ok, gotta climb back in with the salt water fish now, as all I have to do is look up from my laptop to see the deep blue-green of the Atlantic. I guess I'm looking right in your direction but the UK is a bit hard to make out at the moment
)
~~waterdrop~~
I know it has the names but I don't know which match
