4 fingers of cacti

[GregAndrsn]

I bought a small pot of cacti, which I believe to be a psychodelic species.

There are four of them, all about 5 inches long, now that I look at them if I wanted to grow them I should seperate them - they are outgrowing the pot.

But - how much of a store bought variety should I be looking at consuming?

I've seen the peruvians and , ah shat i forgot the other kind, vary incredibly in potency. has any1 got store bought to work? and how large?