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At no time, after any degree of fallow including years vs months, did the system biofilter downsize bacterial numbers, ability, due to missing fish.
Fallowers do not need cycle supplements, new bacteria added, or to help or feed the system bacteria.
pockets of organic waste in the system, pre fallow, are permanent bacteria feed stores. The tank catches it's own input daily from the home as well.
Knowing how to safely add fish back after a dedicated fallow helps. The rule means we don't have to buy and add supplements, things that consume oxygen to help for condition we won't see. You do not have to test for ammonia afterwards: to do so using standard tests is likely to drive panic + reaction dosing: not ideal for fish.
I've read some warnings that are baseless, and cause hesitation in fish handling and planning. Unneeded costs. Surety saves fish.
You can add all fish back at the same time without harm.
*please if anyone has a seneye connected to a fallowing tank reach out. Once you add fish, depending on nh3 levels thereafter, you're set to measure something that hasn't been detailed before in the hobby. You have the only believable kit to make the measure, all else will be convincing us how much green in the sample is significant and why they for sure had to dose Prime.
Per old cycling science, the bacteria downscaled with fish gone, and require time to build up to the new bioload. Any rushing can crash.
No it can't. Disease can crash, cycles hold as long as water is present, fish don't determine tank cycle ability.
Surface area + time + water does. Fallowing fish are not in the equation; so you can add them back instantly and updated cycling science predicts that. Someone seneye test that claim and post results. You'll have reef chemistry article gold on file.