How do you move team galactic when their standing in front of Acuity Lakefront in Pokemon diamond?
you have to beat the snow point city gym leader.
Cynthia's grandmother gives you it after the bomb scare, which is after the Psyducks-ness. You need the SecretPotion to cure the Psyducks. You get that from Cynthia after you battle the Galactic Member you're supposed to stalk from Pastoria (The location you get the the SecretPotion is at the Valor Lakefront).
First, you must beat the seventh gym leader (Candice in Snowpoint City). Then, go to the Veilstone Galactic building and there should be a grunt standing outside by the sattelite that is to the right. Talk to him, and he will talk to you then run away. He will drop an item. Pick it up. It is the Galactic wearhouse key.