If I might make a suggestion - you just spent all that time and effort getting your rocks whistle clean, why not preserve it as long as possible? Ghost feeding with nothing in the tank adds lots of organic carbon and phosphate as well as the nitrogen compounds that you want. The decomposition of organic carbon encourages proliferations of heterotrophic bacteria, and in an otherwise sterile tank, there's not really anywhere for the excess phosphate to go but in to the calcium carbonate of your rock.
There is a theory out there that posits cycling a tank with an organic carbon source (be that food, rotting shrimp, what have you) can lead to a protracted period of new tank instability as the heterotrophic bacteria that consume the carbon can a) facultatively metabolize ammonia and nitrite as well as produce it and b) multiply several orders of magnitude faster than that 'true' nitrifiers like nitrosomonas and nitrobacter bacteria that you actually want to form the basis of your tanks's nitrogen cycle, competing with them both for space and resources. No one's ever done the micro-biological work on this of course, but the suggestion is that that some of the instability people see in new tanks (corals dying for no reason for months after set up, unexplained fish losses) that have 'cycled' according to our hobby grade test kits is because those heterotrophic populations can be highly unstable, and if they crash after you've stopped testing for ammonia there might not be enough of the real nitrifiers in the system to to prevent levels from fluctuating.
The 'true' nitrifiers don't need or even use organic carbon, they get their carbon atoms from atmospheric CO2, and they divide veeeeeeeeery slowly from a bacterial point of view (once every 12-48 hours vs once every 20 minutes), which is why a cycle can take so bloody long. They also don't form endospores the way many heterotrophs can (i.e., they can't go in to suspended animation when resources run out or conditions get bad), which means that unless you're buying specialized bacterial cultures that have been refrigerated along their entire chain of custody, you're probably not buying anything with actual living nitrifiers in it. All those bacterial cultures contain heterotrophic bacteria, which aren't really super useful from a tank cycling perspective.
That long novel was my way of saying that once you set up the tank and are cycling it again, you should consider cycling it with pure ammonia, which you can get at Canadian Tire, or ammonium chloride which you can probably order online. you won't be adding any organic carbon or excess phosphate to the system, so you'll only be encouraging large, relatively stable populations of the kind of bacteria you actually want. That also allows you to dose exactly enough to bring the concentration up to 2ppm ammonia, as if the levels get too high, it can actually become toxic to the bacterial species you want and encourages other, high ammonia specific species that won't stick around when the levels fall. Since nitrifying bacteria are ubiquitous in the environment, they'll show up whether you add a culture or not.
anyway, the tank looks great and good luck!
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