Always err on the nose-heavy side, not tail heavy. Add a little weight, or shift the battery a bit more to make it level or very slightly nose down (less than 5 degrees).

When you're done, be sure to anchor the battery so it won't come forward in a hard landing. I use a scrap of balsa most times, and just glue it across the former in front of the battery, or from fuse side to fuse side, if no former is handy. You really don't want it to shift, and even a trainer pulls 10g turns with ease.

It's far better to worry about where the plane ballances than how much it weighs, especially on a light load plane like the Alpha.

You're gonna have a great flying plane when you're done!

J