How much live rock for my 28 gal tank? (newbie)

When you need bigger quantities, you can go aragocrete--DIY base rock. If you seed the tank with a piece of LR with heavy corralina growth and set it next to a PH, you can start to see significant coverage on the rest of the rocks within 6 months.

Oh yeah, my 20 has almost 50-55 lbs of rock (~10-15 lbs are in a 10g sump). It all depends on the look you favor and the livestock you choose.

 

I think at least the 1 to 1.5lbs also, but it also depends on the type of rock. Some Fiji rock is light for its size because it is more porous which is a good thing. Florida rock can be heavy and not help as much. to tell you the truth, Live rock is something I am always looking for because the right rock can add a lot to a tank. So I agree with ZachB, I don't think you could have to much.