Perhaps shockingly to some, this gets my gold seal of approval
Fish-in cycling gets a bad name for 3 reasons IMO- -The old school mentality (still commonly recommended) of sacrificing "hardy" fish in order to cycle your tank. There is simply no reason as responsible hobbyists why we should allow some fish to be damaged / killed just for the sake of keeping others. Jeta addressed that and I totally agree. -Most fish-in cycles are not planned. They are crisis management situations due to bad advice / not having the proper knowledge needed to successfully complete the process, and they find themselves with a tank full of fish with no bio-filter fighting crazy toxin spikes. -Lack of responsibility / commitment / dedication from new aquarists. It's great to see a well mapped out, researched set of instructions to show how it can safety be done. Most of us who already have established aquariums use a similar game plan when setting up new tanks. I'd personally emphasize that there is a big difference between starting with a new, sterile tank, and one where you have access to established media. Seeded media makes a world of difference and can be the difference between a battle and a controlled process IME. If I had to start from scratch it would be fishless, if I talk my girl into the new 72 gallon I want...it would be similar to what's outlined above (though likely a hybrid established media / fishless unless it's for a QT or hospital tank). The only concern I have is with outlining any particular type of water change schedule. People tend to see what they want and forget what they don't...and 2x 50% per week I have a feeling will become the standard advice given (despite the very clear disclaimers you included). I'm a big believer in letting your test kit dictate when water changes need to be done, not using a clock or a calendar. Since fish have different bio-loads and different phases of a cycle present more risk than others...I think it's important to always know what's happening in your aquarium. If you're new to the hobby, have no access to established media / correct types of bottled bacteria or are unsure if you have the time and dedication it requires to keep your fish healthy...I vote fishless. But I totally agree that fish-in cycling can be done completely safely if a hobbyist is informed, dedicated and takes responsibility for the health of their fish. Well done, and I agree it should be added with the newbie resources sticky in the Getting Started forum.
