Base rock is just rock that not in water. It should be a porous rock so that bacteria can grow in it. Once the base rock is in water and there is a source of nitrogen bacteria starts to grow and walla its lr
. You can use all base rock and start your cycle, you won't be writing about how quick your cycle went. and it will take longer for algae to establish itself in the tank. will come in on snail shells and hermit crabs but it will grow. Question is how quickly do you want that color and how much are you willing to pay for it.
Me I bought 1 piece of live rock gave me something to look at. Then added base rock then went to making my own rock because its even cheaper and you can customize it.