Another General Cycling Question

[karin]

First, yes I'm impatient. But trying to deal with that. Had this question that is bugging me though.

So I"m cycling a 60 gallon using the standard method and brining ammonia levels up to 4 ppm etc. When my tank is cycled my plan is to add fish slowly not at one shot as I don't have the money for that. So my plan is to move my 4 corys over from another tank first, wait a week and slowly add fish from there. BUT, if I go slowly then it seems to me that my bacteria colonies will die back to the amount of ammonia that a few fish will produce. I'm cycling for colonies that can handle the full stock. So in theory, could I not cycle to 2 ppm say, and then slowly add fish speeding up the process and avoiding bacteria die off?

Why 4 ppm?

And yes I am committed to the cycling but impatient as hell so my mind is wondering.

 

[waterdrop]

Yes, this gets asked a lot. The answer is no. The problem is that there are hundreds of species of bacteria available in the tank but we need to create the right conditions for the correct two species to win out over the other species in establishing themselves as the dominant pair of colonies in the biomedia. In general they will win out in the long run but there are competitions in the first six months or so that can be won by other species and significantly slow you getting the biofilter you really want.

The reason we do what we do in fishless cycling is not really to match the biofilter to a particular bioload (a particular full stocking) so much as it is to make sure that the colony pair is large and healthy and operating efficiently. The only way to do this reliably in standard fishless cycling is to qualify the colonies as being significantly larger and then letting them "drop back down" to match the current bioload. The other two possibilities just don't work: you can't "match" a bioload and of course you don't -want- to come in -under- a bioload and then try to bring the colonies upward, that would just be the definition of a non-cycled biofilter!

The "qualifying" process we've settled in to here is the one you've probably read in dozens of threads: Once the ammonia and nitrite(NO2) both finally hit a day where they register zero ppm only 12 hours after the 4-5ppm maintenance dose of ammonia was added, you start a "qualifying week" and watch it repeat this process daily for the week. A "not quite ready" filter will stumble during this week. A fully cycled filter will do it with ease.

What's not seen very much by our beginners is that our choice of a qualifying process is really just a compromise from more or less collective judgement. There are some who like to wait for the filter to be able to accomplish double-zeros at 8 or even 6 hours after dosing, but we feel the 12 hour test is "good enough."

Coming at if from another angle, my practical experience from watching hundreds of cases in fairly much detail here is that dosing at 2ppm seems just low enough to create a fairly unpredictable result, potentially slowing the process sometimes. At the other extreme, we do think of 7 and especially 8ppm as our "too high" point because it definately encourages a wrong species situation.

Also (and I hope I'm not confusing you here) there is the business of easing back on the dosing during the nitrite spike phase (the middle part of the fishless cycle) so that not as much nitrogen will go into the tank overall. When this technique is used, we always make a point of easing the dosing back up to 4-5ppm for the finish of the process. This is different from the case where you try only 2ppm at the beginning or end. If you tried 2ppm at the beginning I'd be worried that the A-Bac population might not be as quickly stimulated and if you did it at the end, in the 3rd phase, I'd be worried that the overall robust set of colonies would not be obtained.

That's a lot of fishless cycling detail to throw at you, so please just ask if I didn't communicate that well enough.

~~waterdrop~~

 

[karin]

Perfectly understandable. I knew there was some reason. Thanks for the indepth response... and yes, I added 11 ml of ammonia to bring it back up to 4-5 pppm 5 minutes ago. Good thing is that I do believe the nitrite is dropping.

Thanks waterdrop.

 

[waterdrop]

ok, hang in there. Your cycling log is probably in another thread, I think I've seen it and we'll keep an eye on it. WD