I always let mine fend for themselvs.
One thing I would like to say to you, and please don't take it wrong. PLEASE start researching animals before you buy. I know impulse is a PITA and very hard to resist, I have given in a few times myself. But the more you do this the more money you will save, and the better the chance your animals will not kill each other in the tank. I only say this because I saw your other thread where you bought it. Luckily this guy will be pretty good with just about anything you get and or have, BUT there are other little guys that would have torn apart your tank.