Adding new sand??

[asylumdown]

Shouldn't be a problem. Just be sure to mix it in and spread it out so that you're not smothering things that are adapted specifically to living near the surface. Otherwise just rinse it really well and you're good to go.

[Aquattro]

Worse thing that can happen is cloudy water for a day or two.

[Slyguy00]

Awesome thanks guys, I just wasn't sure if maybe it would start a small cycle in my tank or not. I plan on adding 2 20 lbs bags. Ill just rinse well and do it slowly.

[The Grizz]

Just dont dig to deep into your existing sand as it might release some really toxic junk.