well to start, you'll need at least 10 lbs to efficiently cycle the tank, but more is better. And you'd be surprised at how much rock a tank can hold...i wouldnt be surprised if theres people with 30 lbs in a 10 gallon tank..tho they're prolly left with like 3 gallons of water lol. But the more the better as far as filtration...however since its only a 10, you're very limited on the amount and size of fish you can have anyways, so overdoing it on rock isnt really sensible imo, unless you just like the look.
Anywho...add it all at once. You really wont be losing much life on the rock, if any. What type of rock are you getting? cured or uncured? As you may already know, uncured rock is just un-cycled rock, meaning theres not enough bacteria to break it down to its final stage. Cured rock is already cycled, so it already has the bacteria.
If you get cured rock, you're prolly not gonna even see a cycle, tho it will still be cycled since the rock is already cycled...and thats what you're trying to accomplish during a cycle...get all the needed bacteria to grow on the rock.
So if you get uncured rock, theres' die-off...that will give you a reading of amonia, and then nitrites (and of course nitrates). If you get cured rock, nothing is dead on it to even cause much amonia (if any at all) so there will be minimal spikes.
Either way, i'd add it all at once. That way it cycles or finishes it's spikes all at once. If you were to just add a bit right away, it will cycle yes, but then when you add more, you're just starting the cycle again (or spikes), so theres really no point in not doing it all at once. The pods and whatnot that are on the rock will for the most part make it thru the cycle or mini spikes, so i wouldnt even worry about them.
this is risky though if alot of the life dies when it hits the non-cycled water though
i just read that part, so i dont really know where to fit it in to my book, so i'll just put it at the end lol. No, its not really risking anything...like i said, the pods and worms and stuff will make it thru fine.
to be technical, you're not really cycling the water, tho many people think you do. When you're cycling a tank, you're trying to get all the bacteria that breaks amonia down to grow on the rocks (or if you're using just a canister or HOB or wet/dry filter(s), then to get the bacteria on the media..same thing tho).
The bacteria doesnt actaually grow in the water column..just on any surface, but mostly the rock and sand. Oh, and that brings up another thing...
Live sand...imo, live sand is just a marketting gimmick to sell sand for double the price. Whenever you stir up live sand, you will likely see some amonia and nitrates and whatnot...so you basically have just started a mini-spike/cycle, so you'd have to wait at least a week...with dry sand, you dont get spikes.
Also, theres this stuff called arag-alive..i believe by caribsea...i hate the stuff. Its just a bag of wet sand thats supposedly "live"...theres not really any pods in there, and who knows how long the bag has been sitting on the shelf...the longer it sits, the more bacteria thats is "supposed" to be there dies...so you're getting less 'live" sand than you may think...
sorry for the novel, and hopefully it helps